If its not your daily driver, i personally think you'll enjoy the gains more and overlook any downsides if they arise. you dont get any of the soft wallowy feel when you put your foot down, its hard to describe, but you feel more connected to the engine.

B&M ? hell yeah. ever used a proper H gate gearchange? well i havent, but i close my eyes and pretend i'm in a ferrari put it that way haha fookin lovely. if your ever in the west mids, your welcome to pop round for a cup of tea and a spin in mine if you fancy it. really tight and precise. they are a git to set up properly, i spent a whole afternoon adjusting mine miniscule amounts at a time, i did it 8 or 9 times in the end but once you get the sweet spot its ace.