In Springform pans, you get what you pay for. The few less expensive ones I've bought leaked and didn't seal right. My German ones are tight fitting, the bottom is heavy enough it does't warp and they work like a charm.
I've had similar experiences with French tart pans, as well. The outer ring may be ok, but the bottoms may not hold up. I will sometimes use my springform bottoms to use on a French tart ring whose thin metal bottom lost shape.
Thanks for the info re springform pans. Years ago, I baked deserts for a local rest. and bought really good pans--after using them many, many times, they all end up leaking to some degree. The solution for a leaky pan ( and also a great tip for cooking in a water bath) is just to use a double sheet of foil around bottom and sides of pan and -no more leaking. For home use, it's hard to justify spending a fortune on baking pans that are only used now and then. I think I'll head over to Linen's and Things--always great to get a bargin!