I play mainly finger picking blues (Hurt, Davis, Broonzy, etc.) but also some slide. I've tried glass, brass and chrome-steel. For the moment I like the steel one. It's not quite as heavy as the brass so it's a bit easier to control. I've always found glass too light, but maybe that's because I generally use light gauge strings. It definitely helps to have a couple of guitars so you can keep one in open tuning. I use my old Yamaha for slide; I find the fact that it's a laminated soundboard doesn't affect the sound for slide playing as much as for standard playing.