Great points to all, and I'm sure a lot more points will come in favor of Studio One. That, and heeding caution to the bumps in the road that Craig pointed to with any DAW. My only added contribution, and I'll keep it to a few is I usually ask the person wishing to change over is "What is exactly your DAW needs, be it constructing music from start to finish, (finish, including mastering your compilation of songs, which is a HUGE plus with Studio One). Are you very comfortable around Studio One's clip launching? (minimal strength for Studio One at present). Are you knee deep in the workflow of your present DAW? (playing hopscotch with DAW's isn't always best for ones creative strategy, though with a few weeks to months that can be fixed with lots of hands on).
Another question, what is your genre, and end game? In other words, that doesn't determine the DAW you choose, but it does pose the question of what do YOU SEE, that makes Studio One fill your needs. Because "more and more mixing and mastering engineers are using S1?" While I'd hope that is true, such users reside in and around Pro Tools (by a ridiculously huge margin). Not because PT is better, per se. But the industry lends itself to that. That said, Studio One is becoming a rising star in both it's mastering page, and more and more production houses acquiring Studio One. That, and home producers are using Studio One more and more.
Lastly, you mentioned your changing your DAW is largely due to your missing plugins, crashes, and lack of support. Hey, that's never good, but Ableton Live like most any DAW is largely very solid. They wouldn't have so many customers otherwise. Is it just possible, your computer is having some instability issues, or the amount of your diligence to keeping it run lean with little other software to get in the way, might be a factor?
My points aren't to send you away. Far from it.

But one has to ask, while you're testing the fellow user's waters (commendable), will your computer, and workflow improve now with Studio One?
I think your workflow will improve (minus the lesser clip launch capability). I think you'll love the extremely lean approach to Studio One, once you are familiar with it. But I'm not sure about your scan crashes, and missing plugins. Support will vary from place to place. While you won't wait weeks for Presonus support, your best bet is simply stay away from support, altogether.
Anyway, good luck to you, and I hope you find results with whatever DAW you decide to stay with.
My experience with Studio One, has been seamless, mostly logical contributions, no boat anchor additions to the program, and most importantly, results. As a DAW, it's the equivalent of a carpenters skill saw. Bzzzzz...