I bought a Thompson bowl gouge. Very nice. I believe the flute is U and not parabolic, which gave me a little pause. The handles are quite heavy, but in a good way.
Like Jerry Glaser who proceeded him, Doug Thompson makes a V fluted bowl gouge as well as a traditional U fluted bowl gouge. Glaser was the first to make a deep fluted V bowl gouge, which he made in various steels and Doug has continued on with that and (correctly IMO) never described that flute as parabolic. The gouge that Doug makes for Lyle Jamieson with the wide flute is also a variation of the V flute, but again is not parabolic.
The parabolic flute was developed by Roy Child in the UK, although Roy never called it that. There are a number of bowl gouges that are now made with a parabolic flute profile.
There is some overlap in the edge profile that you can get from U, V and parabolic flutes, but each also has its own particular characteristics and uses. I use all three flute profiles, but I find the parabolic is the most versatile of the three.
On the 10V vanadium steel that Doug uses, my testing showed that it holds an edge for longer than M42, but there isn't a lot in it as most turners will resharpen when the gouge starts to cut poorly. Doug did also make a gouge in 15V for awhile and that performed better than both the 10V and M42....
Stuart Batty is currently bringing out gouges in 15V but I haven't had an opportunity to test one of those yet. The issue with 15V is that it is a more expensive steel than 10V or M42 and the interesting thing that Stuart is doing is laminating the 15V cutting edge steel to a cheaper substrate that will bring that component of the cost down, although there will also be the extra cost of the Batty gouge 'system', which you may or may not want.
Whether the additional durability of 15V is worth the overall additional cost is something that turners will have to decide.
My experience with 15V is that the 10V and M42 gouges seemed to cut sweeter until they suddenly give up (particularly so with M42), but the 15V keeps cutting on in a fashion for noticeably longer, which is fine for turning the very hard and abrasive woods we get down our way that take their toll on tool steels that need to be very frequently re-sharpened to keep cutting. If you are mostly turning medium and soft woods you may not require that advantage.