You can use all sorts of maps really, with the only limit being the 2,5 GB hard disk. And even that can be subsided by swapping it with a 4 GB or bigger CompactFlash card (133x speed or more).
I have ran my old Go700 on 8.417, 8.562, 8.392 Truck, 9.026 and 9.051 with the full 845.2645 W+C Europe map. Navcore 9 is a bit on the heavy side, so I preferred 8.562. I installed Vocalizer Texttospeech and made full use of ALG too.