Hi Uncle Fester, I went through the same process as you last year when deciding which luggage to buy for my 2012 650 (Glee)
Givi racks for the Glee come in three flavours, all of which carry the 3101 suffix. This identifies them with the L2 DL650 like yours in your avatar, and mine.
The PL3101 is a non-quick release system for flat-based monokey boxes, like Trekkers or the old favourites E45 and E36.
The PLR3101 is a quick-release version of the same, and fits the same flat-based cases. The R indicates "removable"
ThePLX3101 is curved, and fits ONLY V35 cases, and they will ONLY fit the PLX3101.
Givi do not, as yet, make a removable system for V35 cases to fit our bike, (which would no doubt be a PLXR3101)
They make them for other bikes, but not the Glee, and have told me they do not intend to do so in the near future.
I decided to go with the PLR 3101 on grounds of price, interchangeability with different case styles should I fancy a change (or have to replace a damaged one) and, as has been mentioned, the V35 system does not really seem to fit the Glee too well. Look at them tucked high and close on a Bandit or a VFR and they make more sense, on ours they look a bit low and wide.
Have a look here
Comparo bagagerie rigide - Valises pour la DL 650