I have pretty much reduced my choices to DCBS and Midtown Comics. Right now I'm just clicking around on each website to see which one has an easier interface. DCBS has a VERY cool downloadable Excel spreadsheet which is SUPER easy to use. I guess when it comes down to wanting to try a new title, I'll need to grab a copy of the Previews catalog to see what's coming out. I considered Mile High Comics for all of 2 minutes then dismissed them when a rep on the phone told me I'd need to spend $600.00 a month to earn the 40% discount. Before I sign up with an online seller, I'm going to try to strike a deal with my local shop one more time.
40% off or more on Marvel and DC. At least 25% off other comics.
No sales tax in most states.
It's like comic book Christmas every month when your order arrives.
Bags and boards extra if you want them ($0.12 each)
Less flexibility in adding or dropping titles. If you want to try a new series you'll have ordered the first 3 issues before you see the first. Likewise, if you decide you want to start a series after a couple issues come out you'll typically need to get the back issues elsewhere.
You have to know what you want before you necessarily know much about it.
If you select monthly shipping (most cost effective) you'll get your comics later than a lot of people.
Even after shipping and bags and boards my orders are way cheaper even with the 20% discount and free bags and boards my local shop gives
Oh, and my local shop puts recent back issues into bags with a board and jacks up the price 50 cents. Drives me nuts.