Settled on a Huawei U8686 (T-Mobile Prism II / Android 4.1.1) for $70usd new. What I've learned compared to the N900, follows.
- survive with screen protector a drop to concrete from pocket
- small hi-res screen is unnoticeable size in pocket
- replaceable battery
- wifi / bluetooth / GPS
- microSD storage expansion
- standard SIM card
N900 is better:
- Camera autofocus and flash with excellent optics quality (affects usefulness as 2D barcode scanner)
- Keyboard and Resistive touchscreen work always even in rainy weather
- Cellular carrier sees N900 as a "dumb phone" and no problem to use on cheap unlimited data plan ; Carrier forces upsell to new data plan if using Android OS
- Already have one and don't want to buy another device
- Most apps are free as in freedom with open source code and free software license
- 16GB or 32GB storage internal comparable with most high-end phones to date
U8686 is better:
- Make and receive calls consistently with instant and foolproof UI response
- Integration with T-Mobile wifi hotspot call routing ; use this one a lot at home where there is Internet but no cellular coverage
- Pinch/pull to zoom makes Firefox Mobile much more useful
- On screen keyboard works smoothly with easy to configure text prediction
- Majority OS marketshare at its release with Android
- No moving parts
Not sure about:
- Google Android manager allows to track your misplaced phone ; Admittedly this is both a great benefit and privacy concern
- Low signal-to-noise App marketplace promoting a non-libre and advertising supported shit storm of apps that are diminishing in usefulness
- U8686 bootloader is locked by default. Huawei honors requests for bootloader unlock code via a recently-discovered form letter. Alternative Android OS builds for this device by community are not yet available.
- Where is wireless charging? Aftermarket product makers of either device, hello?
Summary: An improvement over the N900 should cost *less* than you paid originally for your N900, and to be a true improvement (at the same price) there would be *zero* binary blobs and proprietary softwares required. Can you make a truly libre phone OS run on cheap ($100) Android phone hardware?