Edit: I should have stated the following when I first wrote this, but with this edit I will. I haven't read any other reviews of this brush; deliberately. I haven't even looked for reviews of it and haven't followed any threads regarding it. I wanted to test it "for the first time", at least in my mind. I couldn't escape a bit of prejudicial knowledge that was sent to me, but I wrote it off as YMMV and I determined to test it without prejudice. Now back to my unedited, except for typos and such, impressions/review.
I wish I was a well known (experienced) brush reviewer so that you all could get a review with more descriptive words regarding the brush, but I'm just a user with varied brushes.
For those who don't have time or the inclination to read the entire review, in a nutshell, I love this brush (so far) and I did have misgivings since it wasn't quite what my other synthetics feel like.
OK, back on to the observations/review...
This is what I wrote yesterday after receiving it:
The Chubby2 Synthetic arrived in my hot little hands this afternoon.
It's unlike any of my other synthetics. I just did a hand lathering with it; of a hand soap that in a pinch could be used as shave soap, but for whatever reason after cleaning a brush it's the first soap I test a brush with. I can't remember any brush of any fiber ever lathering this soap as easily as this Simpsons synthetic just did. I actually expected problems loading the brush and there were absolutely none. It actually loaded incredibly easily.
I'm really looking forward to tomorrows shave. But my initial impression is that it's the most badger like synthetic I've ever had in my hand. As I wrote, I'm really looking forward to tomorrows shave. I will be extremely surprised if it doesn't perform nicely.
Back to today.
One thing I will add to the above. If you're looking for scritch, this brush won't be for you.
VdH (Van der Hagen) was up for todays shave since it was it's turn in the rotation. That's OK, because I have just a few days with the brush and I want to deliberately use it with high priced products and the low priced products.
But allow me to digress. I mentioned earlier that it doesn't feel the same as my other synthetics. One of the things I noticed was that most synthetics once wet, act like a sponge to pull up water, then when put under pressure they dump the load. This brush did not appear to be as critical in that respect. Understand that synthetics, even if made to appear as badger are not badger brushes and typically don't act like natural fiber. But back to today. I decided I'd test that by dipping the brush into the basin of water then loading from the tub of VdH; I normally don't do that with a synthetic. Instead I put the water into the tub to be in control. I did not immerse the brush, not was I extremely careful in not dipping it in too far. In going to the tub I didn't have the huge load of water that I expected. I actually had to return to the basin to pick more water up 2 (or was it 3?) times for more water. The brush loaded incredibly easily, and it was clear to see that I had PLENTY of soap loaded to build my ultralather.
On the face, this brush is incredibly soft, but one can feel the softness even when it's dry. As with many synthetics, it also has backbone, though not as much backbone as other synthetic fibers. I thought that might be a problem with splay. This is a huge brush and if it has too much splay it would be a deal breaker for me since I face lather and don't appreciate fibers and lather up my nostrils. The knot has some interesting qualities in use. Here's where I wish I had better words. It's soft and also flexible, the knot wants to sort of "cling together" to form a knot mass when wet (capillary action). If that happens, and you allow it to go on, I doubt you'll get lather. Instead put a bit of pressure on the knot. The brush is quite soft so you won't rub your skin raw. But a bit of pressure must be used to get the knot to splay just a bit and open up for lather making. I'm not suggesting brush mashing, but a bit of pressure to allow the fibers to separate to do their job.
This brush is far and away the best lather maker in my cabinet. Almost too good. I like to lather for 3 minutes for whisker prep'. With this brush one actually needs to extend the lather process artificially to get that. IMO the speedy lather production was quite noticeable. The lather produced, remember this was VdH which doesn't have a really good reputation, was as good as any lather from any other product in my cabinet regardless of price. It was like iridescent satin with absolutely no bubbles. There was no work or extraordinary means employed to make that lather either. Just be sure to use a bit of pressure on the knot to get the fibers to splay a bit. Other synthetics don't require that because their knots are in a slightly permanent splay and they fight any repositioning of the fibers. That's the best I can describe that.
I've only used this brush for shaving this one time (4 more to go) but when they're available for purchase I plan to have one, and a Case synthetic when they're available. IMO, based on this one shave, Simpsons has raised the bar with this brush. It has everything; softness, backbone, incredible lather making, a relatively low price if the early MSRP is held to. If I didn't force myself to use every brush in the cabinet I could very easily find myself using this brush to the exclusion of the others.
Another shave tomorrow.
......................
Then I followed up with pix.
It's a large brush and I don't do really big natural fiber brushes well at all. But synthetic brushes don't act like natural fiber and I find I can do, what to me are HUGE brushes, in synthetic fiber, and get away with it. The same brush in natural hair would be far too large IMO. The largest natural fiber brush that I want and own is the P8 pictured below.
A comparison shot to show comparative scale. I tried to pick brushes other folks would have.
Left to right:
Simpsons TSN LE P8 Phyl Best Badger, 24x48
Frank Shaving Pur-Tech 28 x 54mm Gen 4 V2 STF black handle syn’
The Prototype Simpsons Chubby2 Syn' badger
Muhle 20mm V2 synthetic w/ faux ivory handle
Simpsons Case Best badger 19x42mm
The brush in my palm, again another comparative shot for scale. I don't have huge hands, but I don't wear womens gloves either.
Compared to the Simpsons Case Best Badger as seen previously. I figured this was appropriate since Mark commented that the brush might be made in a Case. No doubt (IMO) the synthetic Case won't have the same knot dimensions.
You are one lucky guy!)
That would be a great way to study it's unique characteristics and to adjust your own technique to maximize the experience within the paramaters of your limited time with it before you have to send it on it's way. 
