Finished the swap today, and was quite easy. Really the only difference was the modem yet everything still screwed in the correct place. The 1GHz casing was pristine and the 1.5GHz was tore up. The first things I've noticed comparing the two, is that first the 1.5GHz is a million times faster, and second the fan is only on when it needs to be but the 1GHz ran the fan 24/7. Everything works as it should and the 2005 model has the same GPU but 64MB, 167MHz bus vs 133MHz, and two finger tap/scrolling. Definitely a plus in my book. Another quick difference on the 1.5's structure, there are little tabs the cable can run under. The 1GHz didn't have those, making it a pain to organize and keep tidy. So anyone can do this as it's super easy, just make sure it is not a 867MHz model!