Well im debating on which cage to get as im going to be getting rats soon. They both look like good cages but its hard to decide which one. Any personal experiences or advice on which one would be best?
Go for the R-685 for sure. The R-690 has limited space for toys/hammies and very steep ramps for when your rat is older and feeble. You need to modify the cage then. My friend was debating between the R-680 and the R-690, got the R-690 and didn't like and ended up giving it away. she said she would never put more than 2 rats in there.
I took one of my R-680's and modified it into an R-685 for my older geriatric gals. I have 5 in there now, but would normally only put 4. I have 2 older girls who aren't going to be around much longer *sniff*