This is a discussion that I will love as I am myself a technologically advanced person at this time as well.

I think Web based apps is where everything thing will be 10 years down the road specially when "The Network" replaces the internet. When that happens though computers as we know it will change too. Because you will no longer need to have the brains of the computer in front of you.

I have not used web self storage or any web based storage software yet. But the only two I have compared really are site link and web self storage.

First off I threw web self storage out the window. I am a firm believer in you get what you pay for. And it just isn't possible for them to supply a high quality product for the price they offer.

Then I look at site link web edition. I am sure it is a great product, as I use site link stand alone edition now and I am happy with it. I wish it was a little more customizable in some areas but over all I am happy with it.

So I compared what I can do now with my current software and what I would be able to do with web edition. Then take a look at the price. And it simply is not worth it.

For a person like myself with 3 locations and 3 databases on my site link I have now, I think it is something like $550-$600 per month to goto web edition.

If I was starting new though I may choose it. It would allow me to attract a better type of tenant. I find with research I have done in my area that on customer that was from a internet lead as opposed to newspaper or phone book. That the internet customer will pay on time more often, will go into default less. I have found in some areas they generally stay longer but I am not really seeing that.
It would also allow you to perhaps skip having a office, people can pay online, see account info online. You will have less needs of needing someone to take care of that stuff for you. Couple that with a call center and you could run several facilities with minimal needs on office work.

As it is now my locations stay pretty full and I have a good grasp on how we are running things, so the cost isn't justified at this time. As times change and more options come available prices will drop, and I will likely make the change.