But I think Romain's work is of exceptionally high standards. But let's "break it down" if you will:
RG vs Kari - I think they are of equal standards for overall finish but at this level of finishing, we are really nitpicking aren't we. The big different between Kari and RG and Kari and Phillipe Dufour, IMHO, is really around the movement design. Yes, we all agree that the finishing is amazing but I would argue that Romain designed his movement from ground up merging new world design technology with old world finishing. That makes it very special for me, at least over a well finished ebauche. No matter how many bridges or plates one replaces, it is still a pre designed movement. Having said, that, I wouldn't knock Kari back if he found extra movements.
RG vs Phillipe - Not sure if this is well known, but in Romain's business plan for his MBA, Phillipe Dufour was a technical advisor to the business. It was also Phillipe who gave Romain the confidence taht he could actually produce his own watch as his original business plan was very different. Dufour suggested that to truly differentiate, Romain had to take the finishing up to "another level" during the initial stages of movement design and specifically create areas where the finishing can be highligthed. An example of this was the "hollowed out" bridge and sharp inner corners. Of course, the level of detail did not go down as far as the bevelling of the teeth. This attention to detail puts the Simplicity ahead of the Prestige. Having said that, Romain's business model is one of independence, where by he has the facilities to create his own parts. This is evident in the way he has full control over the design of the wheels, so while finishing wise, Dufour is much better, there is some trade off on an in-house produced wheel.
RG vs Roger Smith - I believe this is a difficult match up. Having seen two in the flesh and met both gentlemen, I must say that this is a hard call to compare as it involves two different styles of watchmaking and movement layouts. Given this challenge, I will take the easy way out and make superficial comments (sorry Thomas). Superficially, I found the Romain's movement to be more attractive. I think the three quarter plate hides too much of the inner workings, a while we all know that all bits are finished to the highest standards, I do like the ability to peer underneath the plate just for that extra reassurance. I also want to comment on the dial work of Roger's Series 2. It is phenomenal, although there is a well known example on another forum which has an engraving flaw.
The above is, of course, my own humble opinion. Having met all four watchmakers and seen all four watches in the flesh, I think I made the right choice. Of course, with unlimited funds, I would love to own examples of all four individuals. However, if I had to choose one, I'd still stick with my Prestige. It is not a watch for everyone, as some have made negative comments about the dial and the position of the winding crown. However, for me this is just part of the ownership experience. I value the uniqueness of the dial and movement as well as the obvious "heart and soul" poured into making the Prestige a reality. But most of all, I admire the 8@lls that it took for a 30-something year old who is not a watchmaker to launch a superbly finished, in-house designed and manufactured movement into a competitive market.
*Note that I haven't compared RG to Vianney as I have yet to develop an appreciation of his work. I feel out of my own comfort zone of knowledge to comment in any level of detail.
Gaz