A bix and andy trigger solves the 700 trigger freezing issue and is light years ahead of any tikka trigger I've touched.
So, if I fill it with snow and dirt, it will grind..... so will anything with enough snow and large enough dirt. Conventional wisdom would be that if you see your rifle is filled with dirt, you try to clean it before cycling the bolt like a madman and driving dirt where you really don't want it. Unless you drop it in a puddle while a grizzly is charging you and you need to immediately empty the gun, it seems like a bit of a fairy tail scenario.
I've already had my bolt freeze shut (not a defiance) - that will really put a damper on your cycling ability!
In my opinion, the best person to ask about what action is best is the gunsmith who is building your rifle. My family is a bunch of machinists and I've spent many years working in machine shops. I cannot imagine that a Tikka action (while tikkas are great and I'm truly impressed by them - see last paragraph for details) is as consistent and true as a custom that has gone through a much more rigorous design and milling process, but hey I may be wrong. Would you rather try to achieve perfection with a 2x4 from home depot, or a custom sawn and planed piece of lumber? Some people like Fords. Some people like Chevys. Some people like Pintos. Some people's favorite car is a Mercury Lynx. Again, the opinion of a trusted gunsmith who's assembling the rifle should hold the most weight on what action you use for a build - they are the one dialing everything in and dealing with the tolerances. How the bolt feels is a first world problem (coming from me and the Gucci action).

Would you rather go 0-60 in 3 seconds in a Tesla or a Ferrari / Porsche / muscle car? If your brain surgeon tells you that he prefers a 1" scapple over a 2" scapple, you better order him what he wants or find another surgeon.
All that said, I'm not against Tikkas whatsoever. My dad has two 6.5s that I've done all the load development and drop work on. I'm very impressed with both of them - I was easily able to get consistent half minute loads out of both guns with very little reloading effort. Are they the nicest rifles I've handled, no. Do they do the job. Yes. Will Rosie O'Donnell do the job? Yes. But I'd rather be holding onto someone else given the option! (Great, I think I just ruined Tikkas for myself).