I don't have any experience with Kelty, but a lot with the REI tents.  My personal light weight tent favorites are their Quarter Dome series, which won Editor's Choice in Backpacker Magazine a few years back.  Lots of room, great ventilation, easy set up, very stable, tough and dependable.  They also have great features like the stash pockets, fully opening door that stashes out of the way, adjustable vestibule tensioners and exterior fly door storage.  That helps if you want extra ventilation if you want to sleep with the fly open and keeps 'em from flapping in the breeze. The T2 is perfect for one plus a dog.  For two people, I have the T3.

They did make some changes and have a new model this year.  I have not checked one out yet. 

Their Half Dome series is also very good and much more economical.  I've owned some of these too and alway had good experiences with their tents.

pd