will mini dvd work in slot loading dell laptop drive?

NEVER put a small or odd sized disc in a slot loading optical drive. You will break the drive and scratch the disc rendering it useless.

Use an external drawer loader.

the sony will probably be a better computer. i have a sony and my little bro had a dell, but he got rid of the dell cause it sucked. i love my sony and definitely recommend them over a dell(or anything else) any day. i almost bought that same sony that you are looking at, but they didn't have the color so instead i upgraded and bought another(slightly better sony). but that computer will be a way better computer than the dell even though the dell does have a few other features, and the features on the dell aren't worth that much anyway you won't even miss them. my sony has all the features of that dell, and i don't even use allot of them. also, the prices you have listed are way more than you should be paying for either one of those computers-my sony has more features than yours and is a more advanced computer and i didn't pay near that much. try going to best buy or another place instead of customizing it and you will save a ton of money.