I would also suggest WebSelfStorage. I have used 4 different kinds of software and WSS is the best I've found for our budget. They also are pretty receptive to entertaining your suggestions and requests for improvements. There are a couple things I have had to do as workarounds, but nothing that was a big deal except one, and they are working with me to resolve that now.

We had one site on Quickbooks for a while. It was ok, but not designed for storage issues and that created some problems. That's where I think you're going to have trouble if you decide to go with Excel or anything else not specifically storage related. You can certainly make it work, but it leaves you exposed in a lot of places - specifically, human errors become more of an issue; you're going to spend a lot more time creating and monitoring programs that are automatic in storage specific software (like late fees, gate interfaces, etc.) The only reason we used it at all was because it was already in place at a facility we bought and we had a lot we had to do before we could convert it.

HTH. If you decide to go with WSS and have any questions, let me know. I don't claim to be any kind of a guru, but with multiple sites and about 5 years under our belts, we've pretty much seen it all. I also have kept a transcript of every Tech Support chat we've had with them, so that saves us time. Lots of times, we can refer back to the book and avoid calling in again if some problem reoccurs.

K.