Alx98;
The reason many regard the .300winmag to be "too much" for deer relates to "what does it take" to put down a deer, vs. whats excessive and "over kill". Or put another way, do you plan to eat the deer you kill?
Having taken (legally) deer with most every thing from .22rf to .45/70 loaded to near .458winmag level, to include 20ga and 12ga shotgun w/slugs and buckshot........(except for anything with 6.5mm bore)
You can certainly kill deer with a .300, but if you don't use certain discresion in choosing bullets/loads, you can end up with a badly shot-up deer.
A 150gr bullet with a frontal shot to base of the neck will ruin approximately 40% of the edible meat, and if deer isn't taken directly to cooler, or butchered immediately, will ruin the whole carcass (ask me how I know........ 25yrs experience as a gamewarden/wildlife biologist and over 300 deer taken not to include those shot as depredation/population control/research). I've seen many-many deer taken by hunters besides those I killed myself (literally thousands...)
If you DO intend to go elk,moose, bear hunting; the .300winmag may be the best rifle for you. However, if you "might some day" go hunt the aforementioned game, something with less recoil and expense will be better.
I loaned what I consider my "go too" rifle for ANY N. American biggame to a close friend to go on a "hunt of a lifetime" for ELK. He took (cleanly!) a 1,200lb 6x6 elk with my Remington M7 in 7mm-08. He declined to use my: .338/06, .300RUM, .30/06, because of an old sports injury to his "gun-shoulder. That and at 10,000' elevation, a 11lb rifle is MUCH heavier than a 7lb rifle after walking 7-12mi. BTDT too....
For your purposes, I'd suggest a .30/06. You can never go wrong with the ole '06. But the 7mm-08, .270, 7mmMag, ect. do just as well.
If you do get the .300winmag, use a 180gr bullet(or heavier) and avoid "lengthwise" body shots on your deer, unless you are shooting at a "trophy" and don't care if the meat is "pre-tenderized". The 150's are just a bit too explosive for close range shooting on "meat" deer.