I bought a TVC23 with a BH55 head last fall. I live in LA so I was able to take the drive up to RRS HQ to look and touch before I bought. I had been considering/comparing the Gitzo 35xx series and the RRS 2x series.
At RRS they have (and sell) both Gitzo and RRS tripods in their "showroom" I was able to compare a G35xx tripod right next to a TVC23 and TVC24 and felt that the TVC23 was the sturdiest of the bunch.
While I know the Gitzo tripods work really well I am not impressed with their finish. I know it doesn't really matter but when I handles the RRS legs there was just no doubt they were what I was going to purchase. The build quality of all RRS equipment is incredible, everything is so smooth. The machined metal parts, the look, feel, stability and weight of the carbon fiber legs are just incredible.
The only thing I don't like about the RRS legs is the feel of the twist locks. When you are opening them there is a distinct click which doesn't seem quite right. I would rather they operated a bit smoother but they do the job well.
I've taken my tripod apart and find it odd that having long tripods is a big deal for them. The legs are pretty simple assemblies and I think they could even offer custom tripods at any height required quite easily. I doubt they are creating different tubes other than them being longer for the L models.
All in all I know I paid a little more for RRS but it's the last tripod I think I will ever need. If I use it for 15-20 years it really is just pennies a day extra.