They are different no doubt, but apart from lack of the physical k/b can you guys name top 3 things you miss on the N9 as compared to the N900? No support for Skype video is obvious, but what else?

Copy/paste everywhere, SD card, removable battery, and GTK support, to name 4.

me too had no money 2 yrs ago.

By the end of last yr i bought it even my thought same as you over performance issue (but after i found it can be overclock, i don't look back).

The screen albeit resistive can give alike feeling as capacitive & i'm aware some members suggest n9 but in terms of hardware features, n900 is more complete w/ fm transmitter & infrared)

For $230 you can get brand new from aliexpress.com (on used one, i think varies depend on country for example in china very cheap under $100)

EDIT:
one issue, it doesn't have sim toolkit for mobile banking although some members suggest via internet but sms banking is more robust in remote area (i wonder why nobody post a working stk.apk/sim toolkit app for nitdroid yet while sms is working well?)

price is much more than you should pay coz i bought my N900 in august-2011...a 2 week used one.....in 11500rs. In india with all accesories....means in 210 american dollars....so you should not give it this much money...160-170 is more than enough otherwise the n900 is worth buying anytime...anyday

Before you buy make sure all the hardware is working, if possible.

When you do the first step is a full reflash.
All your information can be found a wiki.maemo.org

The reflash will check the data on the USB is working.

Next steps are installing CSSU, Kernel power (for smartreflex).
Then research about putting your swap on SD card and Thumb (which is part of the Testing Branch).

"backupmenu" can provide a backup of your clean freshly reflashed and updated device, this way you can restore if all goes wrong.

Best one out there. Doesn't need a multi-core CPU to do it, which shows how efficient the o/s is and that app devs can't be @rsed to optimise their code, just like they don't do on PC

No problems with that here.
Just bought myself a second N900 for messing about with. The main reason I've stayed with it is because there's nothing else out there that can or can be made to do as much as the N900, and certainly not more.
My own research has found I'd need to buy AT LEAST 4 devices to get anywhere near the hardware featurelist of the N900 and I'd still be missing out.

By todays standards n900 is a dinosaur. Big, slow and ugly, but still powerful.

spreadsheet and document editing, working mail client, proper file management, mypaint, plus those stated by taixzo

With proper file management I don't mean a proper file manager (thanks CepiPerez) but possibility for other apps to fully utilize the filesystem and not have that braindamaged "supported documents" feature.

And IR, replaceable battery, radio transmitter, color led, camera button, lens cover, kickstand...

The ability to stand outside the local TV/Audio shop and turn all their TVs and HiFi systems off.

Biggest laugh I've had with a phone in a long time.