As said above really. They are 2 completely different cars, best bet is drive both and see which you prefere. I have able to drive both kinds of car working here, and we have had both of those cars as demo vehicles, so have pushed both of them with the performance mods.
The LCR we had was a rediculously quick car for a standard turbo'd one. The ride was a little bit dubious on it though, if you were to get one i would normally recommend maybe some coilovers and at the very least a rear ARB for it. The LCR's, IMO, are still one of the best looking standard cars out there, straight out of the box they are a car that looks wise wouldnt need touching (ride height, wheels etc - not bodykits
). You will need to spend a bit of cash though to get them as quick as they deserve to be. Ideally looking at a full turbo back (with a 3'' downpipe and cat back), air filter, preferably an FMIC and stage 2 software.
The MK5 GTi's we have had (1 manual and 1 DSG) have been amazing cars. As Dan mentioned, the 2.0TFSI engine is an amazing piece of kit. From a remap it will go to a relatively similar level as the LCR straight off, but will kick out more torque. The chassis on the mk5 is again far better than the mk4/leon platform. Also the interior seems a lot better put together IMO. The DSG's are exceptionally smooth, but i still prefere the manual (unless i'm feeling lazy, in which case the DSG is great for tootling and in traffic
). With decent mods and mapping on the MK5 you will get a quicker car than with the LCR thats for sure.
At the end of the day though, the choice is yours. Drive a standard version of each car if you can, and see how you feel in both.