Gday.
I had to update my LR3 to LR4 since Adobe didn't make a newer ACR (adobe camera raw) that would support the 6d (ACR for LR4)
LR4 is good for playing with colours and exposure.
It's pretty useless for image masks and fancy photoshoppy stuff.
So both programs are useful to have.
DPP is also useful to have as its quick preview is super quick.
If I were you I'd google for whether the ACR avail for your Adobe products work for the 6d and get a trial of LR4 and PSE 11
Also, LR4 has a mapping thingo so you can view your pics on google maps. This is handy.
Canon also gives you the MapUtility which does the same (but you need to install the zoombrowser or whatever software to get it)