Definitely not Tikka. They may be manufactured to a high standard of quality control but ultimately, they're designed to be built as cheaply as possible rather than to be the best it can be. They have a cheap bar stock receiver, a bedding system that is designed to be made cheaply, push feed, relatively tiny cheap extractor, cheap plunger ejector, mutli-piece bolt, etc. Oh they're accurate enough, but so is a ruger american or savage or Mossberg. They're polished up to a high standard but make no mistake, the Tikka is designed from the ground up to be made cheaply and is not a quality design.
The modern Model 70 is a spiritual successor to the pre-64. It's got a solid machined receiver with a flat bottom and fully integrated recoil lug. The bolt is a one piece design with an excellent CRF hybrid design. Just unscrew the back of the bolt and the entire firing pin and spring will come out for incredibly easy field cleaning and very reliable operation in cold weather. The extractor is clearly superior and the proper ejector means the shooter can control exactly the ejection power of the round; the cartridge can be delicately angled out about 30 degrees from the action and be plucked out manually, if desired or thrown out with authority. The tikka can only eject one way, of course. The safety on the M70 is a better design as engaging it applies extra compression on the spring which disengages the firing pin from the sear. If there was any mechanical failure or a really bad drop, the sear disengaging will not cause the firearm to discharge because the firing pin is held back away from the sear. You definitely can't say the same about the Tikka. The model 70 has nice steel parts throughout and doesn't use plastic, period. If you opt for the featherweight you get a gorgeous walnut stock which is glass bedded. Their stainless is nice, too, if you're into that.
They both have great triggers that break cleanly without creep. They both have smooth bolts; a lot of people rave about the smoothness of the Tikka's bolt. In my experience, the M70 generally will have a smoother bolt, especially once all the factory rest preventative gunk is removed and things are worked in a bit.
It's up to you but if I were in your shoes (and I have been) I would opt for the design which prioritizes doing things the "right way" or the best way to do things without exception rather than prioritizing being cheaper for them to manufacture. Tikka has a very high standard of manufacturing, but their design is really NO DIFFERENT than a Ruger American. It's just a really well made Ruger American. Does that stack up against a M70? Definitely not.
I've got a M70 that's many decades old. When it came into my hands, it had obviously been hunted a lot and had seen some hard service. It's still doing well and impressed me very much when I tested it at the range. It's got some battle scars, especially on the all steel trigger guard which, though marred, is still intact. Actually the wear on the steel and walnut has left the rifle with a rather attractive patina. I wonder how the plastic part on the tikka would stack up to a similar lifetime of use and abuse. I've seen no indication that the two 'modern' M70s I have are lesser in quality to this great old one. In fact, the machining is smoother and nicer and the bolts are smoother.
The only thing the Tikka does better than the M70 is have a lower cost of manufacture and make more money for Tikka. The M70 is VERY expensive to manufacture. VERY. Their markup is probably not much, but as a consumer that's not your problem. Buy the better quality rifle, you won't regret it.
