Damien,
I'm fairly sure the only difference is spool size and line capacity. The 25000 is a seriously big reel, you won't want to cast it all day and you'll never need that much line capacity chasing GTs. 300 metres of 100lb (PE8is) is more than adequate.
They're pretty good reels and good value for money. The low gear ratio would drive me nuts though, particularly when working stickbaits, but there are guys that do it..some very successfully.
Regards,
Trevor