There's a lot to like about the VPI traveller from a design perspective - it's drive system provides for very quick startup and the arm also has some very nice design features.
Although, I'm not a big fan of aluminum platters, however VPI has used stainless steel as a damper and the belt being around the outside should also assist.
RE; Rega - I own an extremely modified TT that started life as a Planar II with a glass platter - that specific TT was full of poor design choices.
The Rega glass platter, while good for wow/flutter control has a tendancy to ring and fixing that presents many more problems.
I've since replaced mine with an Acrylic platter - which surpassed all other "solutions" that I have tried over 30 years of ownership.
The Rega arms were ahead of their time back then, but I have since had my RB250 rewired with Cardas one piece upgrade and NOW I'm in the process of replacing it with Audiomods arm (which uses a Rega Arm tube)
Being very old school, I don't think I'm quite ready for the Well Tempered Simplex just yet, but it does look very intruiging and would certainly be a conversation piece. Designed and constructed by what sounds like "fanatics" - it should perform extremely well :-)
If I had my time over again I'd go for the VPI also!
Apologies to any Rega fans out there :-)