My two-hander is the more reliable, I will occasionally use slice backhands and the very odd time go all out for a winner off the one-hander (something I've never tried off the two-hander), it all depends on how the match is going and how your opponent deals with the shots. There are some matches when I just can't hit one-handers and have to hit all double-handed and vice-versa.
Ruben Ramirez-Hidalgo is an intruiging player. A complete nobody who near the age of 30 worked himself up to be a competitive claycourter (2006-2007), beating Ferrer at RG, leading Federer 5-1 in the final set in Masters Series tournament.
His playing style is also of interest, he is the most technically pure moonballer on the tour
miles ahead of Nadal in esthetic terms, complete with a never-failing trademark grunt. A legend.
I use a one-handed backhand. Sometimes it's on fire and my timing is right on, but then again sometimes I hit the topspin backhand too soft and a bit late and it becomes a "slice only" shot and thus a significant weakness. My forehand has more firepower, topspin and reliability, but I'm proud of playing with a nice-looking one-hander .