Solid Roller lifters

Hey guys, What's the deal with converting to a solid roller?

I've heard that bushing the lifter bores is necessary, I've also heard it's optional.

What brand of lifter do you consider to be the best/worst/middle of the range?

Does anyone have real world experience to share regarding swapping to a solid roller with the intention of getting a cam that has more idle vacuum etc while also increasing power output?