Okay long-time sonar user here for over 11 years, and now playing with Studio One for a couple days. Here is my admittedly partial and preliminary report on what I see.
Install really easy and I was very happy to see it automatically pick up my interface and even assign the inputs and outputs without me having to do anything! I did tweak them later, but that was really easy. It also hooked up very easily to my Mackie MCU Pro and extenders and tranZport and works very well with them so far.
I was very pleased to see almost all of my plugins, including most of the Cakewalk ones, worked right away, and again we're picked up automatically. My melodyne studio via ARA works perfectly. In other words, there were no major showstoppers and I was up and working trying to learn the interface, shortcuts and workflow right away.
Multiple takes and comping were pretty similar to the way sonar does. I think there are even a couple of things I like better, but I'm not sure of everything is I haven't really done real work with it yet.
Adding effects, adding tracks, adding VCA controllers, buses, effects tracks, and so forth I really like. I would say it's a good bit easier than in sonar. I know one complaint people are having is the lack of track templates, but they have a thing called track presets which are basically the same thing, but not user definable at the moment. It is easy to imagine them making it so however, and I expect you will see track templates in this software within a year.
Rendering was a piece of cake, and they have song start and end markers which make it a whole lot easier than having to try to select all the stuff sonar did to make you export correctly. In fact now that I think about it, I really hate how sonar works on exporting a song.
Automation was super easy, and they've got some neat things like being able to create nice curves on your automation lines. They've got this neat thing where whatever you touched last is shown a little area by itself ready to automate if you want to just by clicking the A button.
To get rid of one myth right away, it was very easy to put my console view on one of my monitors while my track View was on the other monitor just like I do in sonar. In other words, it's pretty easy to undock things from their single window view and move them wherever you want
Overall the feeling is pretty slick and I'm learning it pretty quickly as I get used to how it does things,. The downsides seem mostly to lie in cosmetic things for me. It does not have the full control of color and other UI features that sonar does. As a result it doesn't look quite as cool or modern as the latest sonar with that beautiful tungsten interface. On the other hand it's not horrible and with a little work on their appearance options you can get it to look pretty decent and not too silly LOL!
One thing I don't like is the lack of any kind of decent input or playback metering on their track View on each track. It has a meter of sorts but with no numbers or scales on it.
I have not tried anything with Midi yet except my control surfaces, but I hope to do that on Monday or Tuesday. I do know they will be having a special deal for sonar users to Cross grade coming out on Tuesday. I think it will be around $150, but do not hold me to that please .
In short, I'm liking it over all, have not found any showstoppers, and expect that it's the kind of product that will develop rapidly to having more mature and expansive features.