The HooToos are very nice -- I had some field work a couple months ago where we needed to be able to talk to an instrument over wifi out in the middle of nowhere. We brought two of them along - a TM01 and a TM03. I kept the 03 in the outside pocket of my immersion suit and it was perfectly happy to run all day and didn't mind being cold (-15 C air temp, device in an outside pocket). The instrument was set up to automatically connect to it if it found it, and everything went very smoothly-- we never had to mess with any network issues in the field. When we got them I didn't check first if the firmware can be replaced, but they're cheap enough that I'll probably try it on at least one of them when I have some time to mess around.