I originally had the standalone LR5 as well as the perpetual-licensed CS6. When the PS-CC+LR5-CC was announced I signed up for that, which seems like what you’re thinking of doing, except you have PSE11 instead of CS6.
You will need to uninstall the standalone LR5 but you can leave PSE11 if you want, then do a trial of the Photogarphers Progarm if that is an option, just to make sure PS-CC (2014) is compatible with your system.
As long as you crossgrade from standalone LR5 to CC-LR5 your catalogs and photos will work the same and you shouldn’t notice any difference except maybe a Cloud Sync login when you start LR. The only difference between the two is licensing so you’ll have to be logged in to the creative cloud to use LR5 instead of typing in a serial number after installing it. Your old license for standalone LR5 will still be valid and you can actually install it on two other computers if you really want to have more than 2 active at a time. Of course it’s still tied to you so if you want to give it to someone else, then there is a transfer of license process. I have kept mine in reserve in case Adobe does something undesirable with LR 6 or the cloud and I decide to not use the cloud anymore. Make sure you can find your serial number for the standalone LR5 on Adobe .com before you do anything, that way you have it somewhere, in case you need to revert back to it.
Brilliant sspengel, just what I needed to know. Thanks very much for the prompt reply. I assume I have to deinstall the licence for both programs before I uninstall them?