I purchased them last year for the first time to try them out. I bought them in a couple different stores both in trays and in bulk boxes not realizing there'd be any difference. I noticed there were different kinds when soaking/sowing but didn't think much of it until it was time to transplant and I wanted to remove the netting because of the negative things I'd read about root restriction. One type was easy to rip and peel off- the other kind needed scissors and really slowed things down.
I returned the rest of the bad ones and in WMart they had some 72-cell trays with the good ones but most were the losers. Guess the transition started last season- too bad but maybe the new ones are more biodegradable than the plastic stuff- no doubt they're cheaper to produce.