Looking at building a set of light bicycle 38mm Carbon 27.5 wheels on pro4 hubs.
Not sure if to go for 28 or 32 hole, I’ve seen the Bird carbon wheels and they claim to use 28 spokes to give a slightly more compliant ride which sounds good.
I’m guessing they’d be plenty stiff enough with 28 for hardcore trail riding and the odd enduro or do I play safe and go for 32?

I went for 32 on mine. The carbon rims feel stiffer than the ally rims they replaced, but not like there going to shake your teeth out. Just less flex when turning. I don’t think I ever noticed the flex until it wasn’t there.
Just what your used to I suppose.
I would think the weight saving on 4 spokes and nipples is minimal for md go for strength and reliability and 32 spokes.

Went for 28 but TBH I should have chosen 32 to open up more hub options for any future rebuilds.

32 hole on some 26″ rims and 28 hole on some 29″ rims – all work fine.

In reality I probably thrash the 29ers more as they’re on an Anthem and I often forget to remember that it’s only got 100mm of travel 😳

I think you’d have to be pretty tuned-in to notice any difference on a given rim – are you tuned-in, man?