Some good points brought up so far. I would add the following:
- Winchester just has the better action - stiffer, better extraction, better ejection on the bench, better safety, better trigger. The Remington trigger issues are very off-putting.
- I think the HS precision stock (Sendero) and Bell & Carlson (M70 Extreme Weather SS) are pretty comparable
- In general Winchester has much better beading jobs (I'd say book having to re-bed the Remington)
- I've never followed the logic of the Sendero. Heavy barrels aren't more accurate, they're more heat tolerant during long shot strings. Hunting does not involve long shot strings.
- If you want to run a sling + bipod, the Winchester will need another sling stud. No big deal but worth noting
- In general barrels from Remington and Winchester are comparable, but the Remington barrels off the M24 tooling (advertised as '5R') seem to have an edge. The Sendero doesn't look like it uses those, but I'm not 100% sure.
- Given a choice, at long range I would MUCH rather be in a 7mm magnum than a .300 Magnum. Better performance plus less recoil plus addressing the same game makes it a no brainer. Since the 7mm Remington Mag is the only popular 7mm magnum option, that would be my caliber of choice. In theory 7WSM or 7SAUM might be nice, but they're dead calibers.
Taking all the above into account, a Winchester M70 Extreme Weather SS in 7mm mag seems like a very good choice.