Having put just under a dozen hours into Helldivers 2: Yes it's good. Real good, and refreshingly difficult for a horde shooter at that.
The bug missions keep a decent pace as you incline up the levels, but man, the robots do not fuck around at any point. They are on your ass immediately and non-stop throughout the entire match, and the game isn't shy of just cockblocking you if you're brought the wrong types of weapons/loadouts to deal with the threats its throwing out at you - or if your team isn't coordinated enough. The game in general has a very intense focus on multiplayer cooperation that'll probably do it well in the long run, from having to cooperate to fulfill objectives to smaller things like two players being able to work in tandem so one can fire a high-powered support weapon while another reloads it for them. It's not strictly necessary to do this but it is significantly faster and more effective than leaving one person flying solo with the rocket launcher. Defending your extract with combined minefields, heavy weapons emplacements, and turrets - or laying siege to enemies own camps via combined arms and orbital bombardment - is likewise a good time. Sources of friendly fire are many and varied for the ignorant player, and awareness of your team is as much a matter of your own survival as it is taking an objective.
There are microtransactions though for what little I've looked at them they look fairly reasonable. They're not price gouging you on the premium currency and the costs attached to what little items there are currently are fairly cheap, the armor sets aren't technically cosmetic-only as they do have small stat benefits attached but they're not anything beyond what's available in the main progression tree (medals). F2P (for lack of a better word in a 40$ game) progression is still the meat of the content and is where most of your guns/cosmetics will come from, as well as small amounts of premium currency. It's early days in the games lifetime though so people will have to keep an eye out on how their mtx practices develop.
All that said: do not buy this game right now. There's just no point because the technical issues are extensive and live up to everything you've heard. As an example, right now as I post this comment, half the (massive) playerbase are stuck staring at a black screen whenever they try to load the game. I personally got booted into an endless loading screen after extracting from one of my matches and have been stuck on the black screen since after reopening the game. From what I've been able to tell, it's a measure implemented by the devs in the hopes of alleviating the pressure on the servers until they can get more infrastructure in place in the next day or two. The game doesn't really have any queue or matchmaking system to speak of, instead it's functioning more like a raffle where it attempts to connect every 30 seconds and if there is a spot availabe at that very second, you get in. If not well sucks to suck.