You know what other gun has only one action length? The beloved pre-64 Model 70. Two piece bolt? The modern Model 70. Cheap plastic stock....some Model 70's. Cheap plastic mags that cost too much but work extremely well.....forget that, the Model 70 doesn't even offer detachable magazines, floor-plate only. Its great if you enjoy less functionality with similar complexity and weight. Speaking of weight, that CZ550 is a bit hefty for a .308, no?
For the record I think both the Winchester and CZ are fine guns, as is the Tikka. However, if all three were lined up and I was asked to place a bet on which was the most accurate or had the best trigger, I'd pick the Tikka. If I were to bet on which would be the least ammo sensitive, I'd pick the Tikka. If I had to choose which to spend several days hiking with, Tikka by a landslide. A lifetime rifle to admire and pass to my children, M70 featherweight high-grade, or perhaps a supergrade if in a larger chambering.
Given the OP asked about Bergara and Tikka, lets keep it to that. I have no experience with Bergara so won't comment but to say I haven't heard of many unhappy owners. I think the OP would be happy with either, but I'll put in another plug for the Tikka because it's a known quantity.