Okay, I'm a one-handed player, and I went out to the park and hit some two-handers for myself, and this is how I felt.
It was a different experience to say the least. It wasn't hard to hit by any means, but it was difficult to hit it hard on a regular basis. Maybe my body rotation was just poor because I'm not used to turning my body so much off that wing, but when I did get a good crack at it, it was a solid ball. Low balls were a real struggle, I had no choice but to slice those right back. Balls that came in about waist height were just lovely, I could crank those all over the court. Balls up near my shoulder weren't too bad, I really didn't have to swing up to clear the net and hitting flat balls off that side from that high was pretty easy. Wide balls were also hard to hit, I had to slice those back. Generating lots of topspin was a lot more difficult than with my one-hander. I actually found it easier to disguise my slice because my right hand was in the continental grip, I could set up like I was gonna hit a flat ball and then just move my left hand up and slice the ball. Once I got used to it, it was rather easy to hit consistent rally balls, and was a very repeatable motion.
My final review of the 2HBH after using it for one day would be:
Difficulty to learn: 2HBH
Low Balls: 1HBH
Medium Balls: 2HBH
High Balls: 2HBH
Again, you won't learn anything new from reading my review. 2HBH is a stable, consistent rally shot that's easy to learn and easy to repeat, and will be your best option if you want to be an Agassi-type player, hit hard, flat, and consistent, and grind your opponent down from the baseline. 1HBH will be better if you like a shot that can give you lots of spin, lots of easy power and reach, and is a good shot for people who like mixing up their games.