Tikkas are an outstanding action. Once you get the action blueprinted, custom barrel, bedded, ect, there is no difference. The features on a custom action can be much nicer though. Several years ago I had my PRS rifle built off of a Win Model 70 action. It shoots just as well as if I had it built off of a Defiance but the integrated 20MOA base, smoother feeding, and other features would have been nice to have. If you are tight on cash, blueprint a factory action and go from there. But if you can afford it, I would recommend a custom action.
No need to blueprint the action, tolerances are good enough you can order shouldered prefits for them. I have a few, all are smoother than everything but my impact. Factory triggers don't need to be changed unless you really want to do so. Change the spring and you can have it about 1LB too.