I too have owned Rem 700's and Win 70's. Both worked well and shot fine. In fact the smallest group I have ever shot was out of a push feed M70 in 270 Wby with a friends handload.
I also have Rugers with their crf.
Today, all of my Rem 700's are lh custom rifles, and my two Rugers are also lh customs. I do not own a M70 at this time. Also have 3 lh Sako's, one factory 85, one custom AV, and another factory 85 on its way. The newest rifles are the Sako 85's. The Remingtons and Rugers are all pre-2000, except for a customized Rem 700 lh CDL and lh XCR.
The Rugers were used due to the fact that they were the only donor lh rifles that I could locate at the time for each of those particular builds. One is a 376 Steyrand the other is a 416 Taylor. Both turned out great and work/shoot very well, so I have no regrets with either. Would I have used a Win70 or a Rem 700 for either build if I could have found them; sure.
For me, it originally came down to balance and feel of the rifles that are available in left hand configurations, and their ability to be customized easily (more options available). And for me, I prefer the two position safety of the Rem 700/Sako to the 3 position safety of the Win 70 and Ruger, but that is just me. It is what I learned on first, and am more comfortable using. I understand the preference of others for the 3 position safety, and if that is what you like, great!
I have not changed out any triggers, only had them set to 3 lbs.
All of these rifles will shoot MOA or better with factory and/or handloaded ammunition.
In many conversations with gunsmiths over the years, most issues of feeding issues or jammed actions is caused by operator error (i.e. from hot rodding handloads to beyond handloading manual recommendations, improper maintenance of the firearm, and/or improper adjusting the triggers themselves, to short stroking the action when cycling the spent cartridge for another round, etc.), or from errors made in gunsmithing, whether by a paid gunsmith or a home hobbyist (i.e. over polishing/filing of the sear on triggers to an unsafe condition, setting triggers so light as to render the firearm unsafe in the event of a bump to the stock when a live round is in the chamber, not making proper adjustments to feed rails when chambering rifle to a new cartridge/caliber, not ensuring that the new cartridge feedsreliably when customizing a rifle, not ensuring proper headspace for a new cartridge when rechambering/rebarrelling a rifle, not replacing worn extractors when building custom rifles on older donors, etc.). It all happens. Even the paid gunsmith can or will go beyond what he thinks best, because of pressure from the client, which can be a contributing factor.
Yes, shorter, fatter cartridges can have a tendency to experience feeding issues as compared to longer, thinner cartridges, but for the most part, most of these issues have been addressed.
I have never had an extraction or feeding issue with either the Win 70 700 or Rem in 35 years of shooting and hunting with them in all seasons and terrain/environment types of western Canada.
Even Craig Boddington, who has more field experience hunting around the world than almost any hunter/writer of today, with extensive experience with both push feed and crf rifles in tropical climates for dangerous game, states that in all practicality, that there is no issue with pushfeed actions and their reliability in those climates and circumstances. He has never experienced an issue.
My mentor and hunnting partner over the past 20 years is a big Win 70 fan, and prefers the Featherweights. He has a slew of them, and they all shoot and work great for him. I find his newer ones made by FN in the US, to be the nicest rifles, with better fit and finish and nicer wood, than his others.
But we have as much fun teasing each other about our Rem and Win "jack handles" as any other friends do in their choice of pick ups or other items!
But since we both own Remingtons and Winchesters in other configurations, and not just 700's or 70's, neither can claim to being a completely dedicated fan of just one maker, and must admit that both manufacturers have made great products.
At the end of the day, it is which rifle you feel the most comfortable with, confident in, and provides you with the most features/benefits that you desire, that will be your best choice.
Hope you enjoy your new rifles!