Today, I decided to go with the 3G offering from Dtac because I can keep my own sim. It's 399 baht per month for 1GB with unlimited GPS.

Firstly, it's much slower than wifi. But, the wifi and edge seem to somehow work together to do the navigation (does the wifi help to locate your current location somehow?).

I'll give it a go for a month.

The other option is True which has the 3G and wifi hotspots - I had the wifi hotspots before for my laptop and it was pretty extensive in Bangkok, so that may well be a better option.

Anybody have experience of these?

Also, I've been told that 4G is very similar to current wifi speeds, so that'll be great when it comes along.