I've been promoted to a regular :D .
I think that, once you get used to them, V grades are excellent. Just that when I first started I found it easier to relate to UKT grades. At the time I was trying lots of stuff around 4c to 5b. Lots of these were V0's but there is a huge difference! Also, it's helps when you try to relate to routes (dirty word I know). I don't see the harm in using both up to say V5. After that V grades work much better.
Just to make it worse, I started off using B grades in The Peak!