From what I've been seeing in reviews the basic gist is "the offline single player content works perfectly fine, but the online is a massive mess right now." The biggest problems being Aspyr clearly underestimated just how many people would be playing online on day one and didn't roll out enough dedicated servers for launch day, and even then the servers themselves are notoriously laggy and buggy.
Definitely a real shame as I had hopes this would be a good launch, and Aspyr had gained a decent amount of good will after the Tomb Raider remasters they worked on with Saber got high praise, but nope.
Personally speaking I wasn't planning on grabbing the collection until either 1) a physical edition gets announced, or 2) it's massively discounted on May the Fourth or something. I'm probably going to spend more time playing offline single player, but I know I'm a minority in that regard given the online component has always been a big part of these games.
There's still a chance the collection could be saved if Aspyr work out the server problems, but the first impression will haunt them. Similar to what happened with EA's Battlefront 2, as I heard from quite a few sources DICE did massively fix a lot about the game and it actually became something worth playing well after its extremely infamous launch (such as removing the infamous pay-to-win mechanics), but that disaster of a launch caused a lot of people (myself included) to never later return to the game and go "wait, it's actually good now?"