Would the DLC even fit on a disk with GTAIV. Most 360 disks are nearing capacity already.
The Lost and Damned was an attempt to get people to use Live. Its a big bet by MS and we wont find out for a while if it worked or not.
The PC version of GTA4 is nearly 16gig (got it on steam). But dont forget the PC version needs more data due to having diffence textures qualitys, diffence resoultion sizes and other stuff the PC version has. But im suprized it all fitted on the 360 disk.
PC gaming rules.....