I have a Gates belt on my Ion GPI so not really what the OP asks but it is lasting OK considering it has seen some right filth, 1416.5 miles according to Strava. The belt can get a bit squeaky when dry but a squirt of silicon sorts that. I am not looking forward to replacing it due to the cost of the belt and rings.
I also have a Pinion hardtail. I chose chain drive because it is way cheaper, will last ages and doesn’t actually require that much maintenance since I stick the chain in a fryer full of Putoline every now and then. Only downside to the chain is I do have to retension it once in a while as it wears, presently 975.2 miles on it (I have considered a tensioner for this reason amongst others)
So in short I don’t think belt drive is worth the expense unless you need to keep your flared trousers grease free or just fancy having a belt drive.