I have one of the 1st 100 HMH TRV's & I also just got one of their new 2nd gen jaws that does have a better finish. I am a big vise collector and I am lucky enough to own a LAW as well so I can give you a good idea of what you get compared to a LAW and just how the vise is in general. Also, if you are going to the International Fly Tying Symposium I will be one of the pro tyers there and will be tying on my TRV so I can show you in person.
It would probably be easier to make a video and I might do that if I have sometime but for now Ill go over what I like about the TRV (I have the exhibition with brass base)
The jaws of the TRV are cast compared to the LAW which was machined and then hand finished by Lawrence Waldron
The new TRV jaws are still cast but they are not as "rough" as the original casts were and have a darker finish (its almost black)
The original wheel to open and close the jaws was very "sharp" and hand hard edges. Jon Larrabee (owner of HMH) quickly made new ones where he rounded out all the edges and its a lot better. He swapped out the wheel when I saw him at the Fly Fishing Show in Edison
Performance of the TRV is very good I have put a 4/0 - 26 in it and it hold fine
adjusting the angle of the jaw so you can get the hook inline for true rotary is nice (you can't do that on a law)
The fit and finish overall is very good, the brass base is nice and heavy and the rest of the HMH components are from their other vises where are all top quality
The grooves work but I like the ones on the LAW better.
If you happen to have the chance to get a LAW I would get it because overall its better (in little ways) but the TRV is the closest most people will get and it works well. Let me know what questions you have and I will be happy to answer them.