I have one for my .300bo Mini, works well, would recommend it.
I've used it with both GI metal strippers and Thermold plastic strippers.
Seems to feed smoother with Thermolds although the GI strippers are better made.
Of course, the downside is when you factor in the time to pre-load the strippers it's not a big time saver overall. But for fast loading at the range, worth it.
I also had a gen1 Maglula for AR mags that wound up as a spare when I got a gen2 loader as a gift, so I took a file and opened it a bit front to back for Mini mags. It's not perfect since it doesn't have a side notch to lock in to, and the loading cam lobes are just barely narrow enough to clear the Mini feed lips. But an alternative if you don't want to mess with strippers.
Another alternative if you're not running a scope is that aftermarket stripper guide that uses the rear rail mounting holes. That was my original plan when I wanted an Ultimak railed handguard and a red dot but not sure I want to give up the lo power scope I'm running now.