Downloading is bad. Don't do it. Konami especially deserve your cash. Feel free to download and distribute FIFA however and maybe they'll stop making it. ONLY KIDDING MR MODERATOR!!
Anyhoo, I like the PC version for the enhanced graphics. I too use an adapter so I can use my PS2 pad and it works just the same as a PS2. No slow down on the PC version either (if you have a decent PC). I will always buy the PS2 version however, because it has the live multiplayer element that you have with your mates. Can't top it.