I think the suspension could only be considered ‘dated’ because there are so many new designs coming out these days, things like the Yeti SB66 switch design and the whole host of dw-link and vpp frames around.
It depends what you want from the bike. It doesn’t mean one bike is better than another because a suspension design is newer or more complex (the Covert is essentially a single pivot which is rather straightforward from what I understand), if you like the feel of the bike then that’s all that should matter.
For me, I like how predictable the Covert feels, I used to ride an Enduro (FSR design) which was a lot harder to pop off lips and things in the trail etc, I think this has a lot to do with why people describe the Covert as being a fun trail bike.
With a good shock like the rp23, monarch, dhx, ccdb, you can dial things out like pedal bob, and get the shock working in a good host of situations. I get little suspension bob on my bike, but it is as plush as my Enduro ever was (with a coil rear end) and feels bottomless on big jumps and drops.
I would go for the 2012 if you can afford it, it would be nice to get a wheel with a maxle 142×12 for futureproofing, itlooks like a lot of new frames are taking on this new ‘standard’. I don’t like the graphics on the new ones although the blue is a really nice colour.