Internal HDD is a must for Fat PS2s, it's easy to install FreeHDBoot if you have either FreeMCboot on a MC or a modchip, you need to get either a SATA network adapter the gamestar one (works well though no ethernet port), or modify the OEM one with a SATA adapter board, both are the same in terms of performance. Highly recommended.
It is, for those who just one to revisit & play their fav games and are new to this.
I know about this, it's just considerably more extra stuff one needs to do in order to set it up opposed to this method(MC2SIO), again specially for first timers.. though i personally i wouldn't mind it, but since i use my Fat as my main system i don't see the need for it, maybe if i ever was hard pressed to use my Slim for whatever reason..
Good to know, i guess at least it's better than USB, though game compatibility between the two is something to be considered as well..