I have both, Rem700 Sendero 300WM and Tikka T3 Tactical in 300WM. I also own a Rem 700 VSSF in 308. I have them all topped with top of the line glass (leupold, NXS Nightforce, and Vortex Razor). All shoot incredibly well. When shooting under 700m with match ammo, the T3 out shoots the Sendero, ever so slightly, however on further ranges the Sendero is better routinely. It should be noted both are sub MOA, so the slight difference may be just my good day/bad day situation. When splitting hairs it's hard to tell. With heavier projectiles they both handle wind well, and can really reach out.
For hunting I have carried all of them one time or another. The T3 is slightly lighter. The Rem take a better beating. The Tikka is noticeably shorter, not sure if that would make a difference.
Price wise, my T3 was over 2k with tax, the Sendero was under 1500. The Sendero required 20 MOA base. Hope this helps, if you want side by side pics message me, or if you have any other questions feel free.
Ps
If I was to buy again, I might look at T3 with cadex like chassis, or varmint given the price break puts it in line with the Rem. I have no regrets with what I have bought.