I bought mine a few weeks ago now. Have been doing nothing but playing with it. Now I owned a 6600 for over 2 yrs and a 6630 for about 6 months. Meanwhile I've played with everything from 6620, 7610, 6682 and so on that belonged to my friends (and also most recently with a E61--all that to say that I know quite a bit about S60 and all the questions and problems associated with the platform and Nokia phones.
Coming from 6630, which was almost a step down in RAM from my 6600, I was very weary of N73. Initial research wasn't very comforting as to its RAM abilities. Having now spent two weeks with it, I'll tell you that I am very pleased with it with respect to RAM. It boots up with a few KB shy of 20MB of free ram. After using it for a while it will stabilize at somewhere around 12-13MB of free RAM (so far I havent found an application that will actually compress and effectively recover the lost ram). Having said, I can browse large and complicated web pages in both the Web and the Services browser, like I couldn't ever dream of with a 6630. I never have programs crash on me because I'm running out of ram. Yes, when browsing very large web pages, and doing so for a long period of time, continuously, all or all but one other program will close out, but that is perfectly acceptable to me, as long as I can keep browsing. I havent even had the need to install Opera mini (which is what I resorted to with 6630, just to try to browse some of the larger full websites).
Otherwise, you can run an essentially unlimited list of progs at once and not run out of ram. Same goes for Camera AND gallery simultaneously.
As far as speed, I will admit that without a doubt the N73 is slower than my 6630. In some things it runs at the same speed, in some there is a little lag, but nothing is unbearable. The camera does takes 5-6secs to start from the moment you open the cover--I just stop watch timed it. After that you're about a second or so from focusing and another second from taking a picture--trust me people that is acceptable for the device you're using. If you want instanteneous, drag around a DSLR camera. Even my fully manual semi-pro Sony V1 camera has a lag in boot up and focus, of course not as bad as this. Gallery, if not already open (or open in the background, you dont actually exit it, even if you think you did, it just runs in the background--unless u use a task manager to close it) takes about 2-3 sec to start and display the last taken photo full screen. I have run out of memory almost every time I've tried to zoom in on a full 3megapixel pic--that's about the only time I run out of RAM on this phone.
I should add, that the phone has essentially never crashed on me, except for once when I was doing something very weird with a very weird ringtone file.
Hope this helps. If you have any follow up questions, post and I'll be more than happy to answer.
