So it looks like the hinges tend to rust. I guess it would be good to keep them silicone or lubed up, being careful of course. You don't want the spray or lube to go in the sump.
I do have another stand for a bow front tank that is NOT red sea. The doors don't fit right, the particle board around them is wearing so they will never fit right, the braces have come out, etc. Cheap crap. I will have to replace it at some point.
I think with the red sea stands, if you can keep them relatively dry, (I spill a bunch and its fine) they are very heavy and well built. I say dry because the 170 stand i got used looks like there is some damage at the bottom inside from flooding, but I have never had any issues with it. It is still very sturdy and straight.
I prefer the construction of the S 650 (I have not had one) because its aluminum frame with panels. The reefer is heavy duty and well coated particle board. It comes with some rubber gaskets for where there are pre-drilled holes for construction. Surprisingly not for every hole, but also designed that there is no exposed particle board near the sump. I would be very cautious to drill it though, as moisture in the particle board could be problematic. The stand, sump, and tank on the reefer 525 is exceptional quality. The plumbing is OK, could have a better gate valve. The ATO is garbage.
The doors have stayed perfectly straight for almost a year, proving that the stand is not warping. The stand did settle a bit once water was placed in the tank, but has stayed there since.
There is a rubber mat for under the sump and under the tank. There are feet on the stand so if you do spill it goes under the stand. I like this better since it can dry out, rather than keeping my wood floors wet. We made shelving for the dry side, since you get nothing there. (box construction, as not to drill the stand)
I'm now curious why you are asking about the stand.
Are you comparing brands, or just stands?