[lattesurf]

superstar , personally i own the 4GB T29, but generally i could still comment on the other choices.

1. i would recommend the T39 as it's the latest player from Teclast. It does not differ that much from the T29 or C280 as internally both players use similar hardware. The only obvious difference would be the touch controls though.

2. Not very sure about the Onda, but with a 1000mAh battery, it should be quite lasting. The T29 i have lasts for about 14 hours of music playback, and about 5-6hours of video. I can't remember, but i think the battery is around 600mAh or so. So the 1000mAh batteries for the Onda and T39 should almost double it.
So far have used my T29 for about 10 months now, and it has been trouble free.

3. In general, all players need a little getting used to. The first time i used the T29, the joystick was extremely hard to navigate. i kept hitting it wrongly and going all over the player. But once i got used to it, i could navigate it within my pocket without taking it out.
The Onda uses a stylus, which i presume that control should be quite easy. But troublesome when you are carrying other stuff in your hands and you actually need both hands to use the stylus and hold the player.
The T29 uses a joystick control with some side buttons, the T39 i assume it is controlled by side buttons.
For the C280, it uses touchpad controls. Very much similar to the LG KG800 Chocolate mobile phone. i own this phone btw, control is quite ok, just need a little getting used to. You'll tend to exert some force on the touchpad at the beginning, as you would normally do on normal button controls. But whether it lasts or not, i'm not very sure.

4. In general, all the 4 players uses the same Wolfson audio chip. Which means that all of them are quite similar in sound quality. The thing i like about these few players are that there is a separate audio processor and main processor. Which mean better quality for music. i'll say that the sound quality would be much better than typical nano-clones.

5. Not so sure about the Onda, but the Teclast do have updated firmwares which you can download and update your player. But the last update i had for my T29 was about 6months ago. They probably stopped supporting it as newer players are out.

6. You can find lots of FM transmitter on ebay or your local electronics store. They use the typical 3.5mm plug which you plug into the audio socket of your player. Chose an FM frequency, then use your car stereo to tune into that frequency.
i'll suggest that you check for the frequency used on the transmitter before buying. Most cheap transmitters only have 3-4 preset frequencies, which might be the same as your local radio station's frequency. This would interfere with both transmissions, and you won't get clear output.
If possible, get those that are adjustable, like a car stereo, but are more expensive though.

8. Houseofdap is currently the official main exporter for the Teclast players. But there are some other private re-sellers who sell the OEM version of the Teclast players. They are exactly the same, only without the Teclast branding.

9. Guess i could not really chose the best player as i only own 1 of them. But if given the choice, i'll probably try the T39.