ah, my kind of thread!
got a ps3, xbox, wii u here, brought from uk.
i play all online, not chipped.
im on a relatively slow 3mb/s download speed, well its slow when considering i connect to the eu psn for games, but GTA5 shows very little lag. you can still download uk games if on a uk machine but yes they are uk prices, GTA5 cost me £49.99 but a chipped console with a 5rmb disc wouldnt work online, and title updates unavailable on xbox i believe (pc download and transfer would still work on ps3).
i only play ps3 and wii u online as its free, xbox needs gold membership.
unless you have a decent collection of friends, i wouldnt bother with online, i think bots on call of duty are better than camping strangers on the web!