Can someone please tell me about leappad learning system vs leappad plus writing?

[lunavix]

Want to get one of these for ds for christmas. We had the little touch baby one which I was appalled by, but apparently these are much better

He's 3.7 and I think both are for age 4-8, but I can't really tell the difference...

We've got a 'Leapad Learning System' - was cheap in Argos last Christmas. My 3 1/2 year old loves it - has been especially useful for long car journeys. Also, the games are £10+ in most shops, but if you type 'Leapad' into Google, there's a site that sells them for a fiver, with free P&P. Actually, you could look there, to buy the Learning System itself.