Sometimes you just need to look at more tooltips than the default UI shows. LinkWrangler allows you to open multiple linked items all at the same time.
When I’m cycling through my gear trying to figure out which two rings are best (out of the six I have) I’ll whisper the links to myself and then open them all up side-by side.
The tooltips are minimizable, and can be freely moved around the screen.
Be sure to get LinkWrangler-Auctioneer if you want to also see Auctioneer data in the tooltip.
NOTE: This screenshot was taken on the 3.3 PTR. So at this point LinkWrangler is 3.3 compatible.