Drupal is great. I've used it for several mid-scale community and personal websites, and so far is giving us very good results. I would support the comment pointing at the over-done or even low quality of the templates of many of the website's we've looked at out there, but then, just hire a good coder/designer that does this nicely for you.
As for the memory issues there's tons of articles out there that would help you in tweaking Drupal's database management. There's even a module called Drupal Tweaks that does this automatically for you. Here is an excerpt from its project page:
... provides following functionality:
- Enabling and disabling modules through autocomplete suggestions
- Quick search for the nodes, users, etc. to make some operations
- clear the cache and rebuild permissions from one place or do them both at once
Overall we are quite happy so far with Drupal for quick development of the most varied websites and corporate Intranets.
