I have not had my hands on any U-Tech since Sikkens bought U-tech in 2000 but if the guy is suggesting the 3.8 SS, back then is was better then anything out there at the time.
An excellent polyurethane that buffed good for about two weeks and it would lay like glass. Don't know if its the same now or not.
The 2100 was designed in 1998 as a special project a one coat High solids, polyurethane clear to go with the one coat base also a special project for a particular customer, if its hard as a rock now, then its not the same product, so that leaves me questioning the 3.8. The 2100 and the 3.8 was very similar to the SPI Universal clear. (Just my opinion, of course)
The 200 SS was the cheaper SS in Utech and I was never a fan of that product, if they still have it in Sikkens, I don't know and it may be totally different now.