Gliffy : An online visio killer?

Since the time I shifted to linux, I have always missed Visio. There are some nice linux alternatives like Kivio and Draw but I still find them buggy and a little painful to use. I just need some tools to draw simple ER or UML diagrams for school software engineering projects.

Enter Gliffy, an online visio.. alternative that is not rich on features but enough shapes and diagrams for all your software engineering and basic designing needs. It also has nice collaborative and sharing functionalities and an easy html embed/publish option. I also like the revision history tracking function.

Is it a visio replacement?
Unfortunately no. It still has a lot of quirks. For instance, the keyboard shortcuts didn't work as expected and the Shape templates are quite limited
Overall it is really good start. The basic version serves all my needs and I plan to stick to it for a while.

Do leave your comments on other visio alternatives that you use. Maybe I can review them together.