My origin is fantastic. You have to look pretty hard to find a negative, but if I were to list some they would be:
1) The bolt is fairly loose in the receiver when it's pulled all the way back. I haven't felt a whole bunch of custom actions so it may be common among actions. I have zero issues running the action in the field though, so like I said if you were being super nitpicky you could maybe say that was a downside.
2) I would say the bolt doesn't run in and out as smoothly as a Tikka, but it's pretty smooth none the less.
3) The bolt knob options are awesome, so it doesn't really matter, but the bolt handle is not threaded in the fairly standard 5/16"-24TPI, so don't plan on using any after market bolt knob.
One point about your switch barrel idea, I'm sure it will work just fine, but you might want to take a look at the price of your second bolt head before you commit, I think it's going to be around $200 after shipping but check with them. I had considered a similar thing until I saw the price of another bolt head and my thought was that's a significant portion of just buying another action. Food for thought.
Also, not sure if it matters to you, but the Origin is extremely popular and as a result a lot or maybe most pre-fit manufactures offer barrels for it. In my experience pre-fits are much more commonly available then they are for other custom actions. For me this is a big plus and a reason I'd choose an Origin over many others.
Have fun!