I've been a long term tubeless user - 10 years+ However I've always used proper UST tyres and rims.
Recently I was tempted (by price) into buying some "tubeless ready" tyres (Scwalbe Dirty Dan for the boggy stuff) and fitted them to some proper UST rims using Stan's sealant.
1st problem: pain in the arse to inflate with a track pump. Took mucho sweat and swearing - I'm used to UST just popping straight on no hassle.
Once they were eventually on I span 'em and shook 'em and turned them in all directions to distribute the sealant.
2nd problem: in the shed the front tyre stayed up the rear kept going down. Got the bike out and put it in the car - back tyre stays up for the hour and a quarter journey. The previously ok front one goes down!
Get round the ride (2 and a half hours with some air loss but not enough to get the pump out). Journey home - same thing with the front tyre!
Is it me or have I "got what I paid for"? I've never had any of this cr*p with proper UST.