Here's a personal factoid:
The three people I hit with the most often all have a 1hbh. One is my son who is 17. He switched from a 2hbh about 4-5 months ago. He's hitting it really well - can take balls on the rise and hit aggressively across high balls. The other two guys are my age and are both around 5.0 level.
I have a 2hbh btw, one handed slice.