it depends a bit on how you are going to work with the data.
I have used a QStarz BT1000XT with lots of pleasure, but the drawback it will not work nice with a iphone of ipad... So if you work on a pc then you should be fine.
there is a lot of software from QSTARZ for the normal phototag, trip, sport thingies. But stable nope
Would allow me to tag for 2 weeks holiday easy. And will work for 12-16hrs also.
But it would not talk to my iphone unless i hacked it sooooo....
Recently i got a Bad Elf GPS pro, not as cheap, and a bit bigger, but this one does work with an iphone, ipad giving you the option to download your tracks to the iphone as you go.
This gimmick comes in handy if you are doing multi-day trips and you want to separate the tracks or simply need to store a lot more or a lot more detailed stuff.
Not sure if it is as smart as the Qstarz, which can change the number of points needed depending on how fast you go. Otoh you can change that with the Bad Elf on your iphone as well.
The data files are gpx, htmlx which should help you tag in lightroom.
One big plus, it has a display so you get a bit more info as lock or no lock on satelites, it even gives you a heading. Hmmm would be nice to have a find your way home function.
One Tip, make sure your gps and camera have the same time/date! Especially abroad.
Olympus: E-3, 12-60SWD, EX25,EC20, FL50R, 50-200SWD, XZ-2.
Thinktank: Rotation 360, Change Up, some modules