should i buy a futon or a sofa bed for my room (as my bed)?

my bed is huge and i want some more space.. which one should i buy? which one would be better? more comfortable?

futon: http://www.walmart.com/catalog/product.do?product_id=8032724

sofa bed: http://www.target.com/Sofa-Bed-Black/dp/B0015C7HEE/ref=in_de_detail-buybox-with-variations/601-8422972-2311355

DONT want a futon, very uncomfortable, slept on one as my bed for one year and never again! Go w/ the sofa bed.

where is a good cheap store to buy futons in Toronto?

Try craigslist.com