I have both versions from Vapage (Isn't Vantage a cigarette brand? LOL) in 1.5 BF. They both worked on my Grand, Mini, and miniwoodvil REOs without shorts or connection problems. The new version 2.0 which is all they sell now has a white washer attached to the bottom to prevent over-tightening shorts.
I never tried the Top Feed so can't help you there for differences. My version 1 BFs would occasionally clog and start autofeeding, especially when it was hot in the summer. I haven't experience that with my Version 2's yet, so that is one improvement.
They are nice because the atty never really floods.