would depend on what your trying to do with it. any of them will give you lat long # if looking for that to use in conj with a radio for emergency. if you get one with a track feature which i belive most all have now you could use it to follow if looking to repeat a troll. there does seem to be a conspiracy about handhelds and not having compatable lake mapping software.one with topo maps in it will show you on a lake but they dont make one that has any depth charts. i looked around alot last year as i wanted something for ice fishing as were driving around on the wheeler. hope this helps.