We have GE 'dual fuel' range that is gas on top with gas oven and optional electric convection oven feature.
I do use it, though not regularly - usually when I'm in a hurry - and it does make a difference. I can't say that it's a make or break thing, but it's nice to have.
Honestly, if it's just to bake cookies, it's not going to help. And be careful with 'small', the last thing you want to have happen is to be in the middle of preparing dinner for a party of 10 and realise you can't get your roasting pan in the oven. I REALLY wish I spent the extra money to have a slightly wider oven to accommodate two 1/2 sheet pans/roasters/saute pans side by side. It make things much easier (I cook a LOT).
(Oh, and I know that you said that you really don't use the oven for anything other than cookies, but remember that any future prospective buyer of your house may do more than that. It's definitely something I would hate having to deal with in a new house.)
HTH
-m
Wife to Jonathan
Mom to Sophia 12/02 and Amelia 12/04