Well It isn't cheap and the price IMHO is not worth it for just a dive computer. My bet is that there will not be a completely new model for a year or so.
It does have some simple features that many computers don't like 90L, 90R and reciprocal which makes box nav easier for many. It also has lots of user definable alerts like tank reserve pressure, depths, ect. Live calculations such rmv and sac.
It is very good as a smart watch and the battery life is insane. It as many features that no other "just" dive watch has or if they do, I have not had luck with the features working as expected. Things like notifications, music, gps, apps, heart rate, ox, an insane amount customizable watch faces, pool mode (very useful so it doesn't fill up my log) and freedive and such. All buttons are fully customizable for quick access to something and after you use all of the buttons for quick access you can use button combos to add more.
It does have a payment system which at first I thought would be worthless. However I have used it on many trips when I do not have my wallet since my plans for diving always seems to change as a day goes on. So the wallet has been used many times at a dive boat and filling tanks down by the shore and I now use a quick access button for it.
I also thought the music would be worthless but for pool sessions and boarding in the mountains it is nice to not carry something else.
The GPS is also quite accurate if you use it as intended for diving and it tracks my snow boarding or atv laps quite well.
As far as holding up I have probably been harder on my mk1 and mk2 than most users. I have worn mine as a daily watch since it was released. I have had over 30 days snowboarding, tons of hours ATV riding, months of rock climbing, a summer of pool days and now over 100 dives with it. Sure now It has only a few scratches on the super tuff bezel (surprising it isnt shredding from climbing) and a small nick on the sapphire glass that I have to try hard to notice.
The things I do not like about Garmin for diving is not having a customizable screen that I can put full control compass on with AI. There are many screens that have a place you could swap it out for...but you can't. It would also be nice to have a surf gf..
It also has a beep.....sonar. While this does not bother many I can hear it even on low. Though on low it doesn't disturb me on my dive anymore like the default setting did.
The thing I really dislike about the overall setup is that the dive log is online only. If you do not have web access you aren't logging using the app until you do. So if you log dives you will most likely have to take notes or log later if you go far offshore or dive in a remote place in the mountains.
It does have two types of rx/tx for the mk2i/t1 that seem to bother a few and a handful of people have had issues with it...teething of a new product.
When they do release a new model I would not expect future support unless it is something critical. But in the case of the mk1 it still works well It t just isn't getting any new feature sets.. They are a large company that produces a ton of smart watches and always will want you to buy the latest and greatest feature rich item.