The 36"x18" foot print is nice if you are space limited on width. I have used 40 breeders before, but would like the height of the 65. The only limitations is the length of the fish you can keep in them. Overall, I am a fan of the 65.
Terrible picture but its how mine is currently set up (minus the Sen's & pictus if you can see them)
I'm loving this tank as well. Its my first step up from a 20g, got it for free from my sister in law . Now I've got a 55g in addition to this...as long as the glass doesn't bust while my cross-brace is broken
Going from the 65 to the 55 I definitely see how much I LOVE the extra depth. Eventually I want a 5'x2'x2' tank, I think that would be ideal for me for a very long time. Won't happen for another couple years though. For now I've got what I've got and thats how its gonna have to stay.
edit: also minus all the SEMI aquatic plants Petsmart got the best of me
After a little research into my options for a larger tank in my apartment, I decided on a 65 and couldn't be happier! I would like to go longer in the future (in a bigger home), but this size will definately be a mainstay for me. Actually after getting this tank set up it was my non-fishkeeping boyfriend who suggested the future upgrade