Treadmill advice

My wife and I are thinking of getting our first treadmill soon. Although I love DIY in many realms, when it comes to something big and heavy that could help (or hurt) our failing joints, I'd rather just buy a quality new treadmill that I can trust.

I've seen countless posts on this forum over the years with people trying to revive dead treadmills, so I thought the other members here might have some useful experience. It seems there are a few common failure points. I'm assuming some brands or models tend to be better than others. Any advice?