A used Precor 546 is a good machine. About 4K new, anything else or anything less is a total waste of money. World-class runners like Alberto Salazaar helped develop the Precor and it is the ONLY elliptical that has a stride that biomechanically approximates a runners stride.
If I were wealthy and had the room, I'd have the 546, a stepmill, and a Concept II rower. Since I'm a broke-azz, I'll make do with the rower, a Pendlay barbell and some bumper plates. The last two will do more to toughen your azz up than anything else, and that's a fact.
I'm a fan of elliptical machines for the low impact. There are a lot of good elliptical machines out there. I think Precor is the best I've used, but approximating a runners stride isn't the end all of rating one. As long as it is biomechanically correct (no joint torque, natural movement, etc) the motion can have a wide range. It may be better NOT to approximate a runners stride in some cases.
Pendlay makes some great bars. I been using one of their needle bearing bars with their econ plates for a number of years now. I picked up one of their ladies bushing bars for my wife and wasn't as impressed with it. Big difference in the spin between the two but for most folks it won't make a difference.
