The main difference between the two is the pinpoint mode on the 250, which the 150 doesn't have.
That's why I went with the 250 instead of the 150. The lower resolution ID mode means much less to
me than the lack of a pinpoint mode. So if you have trouble locating objects, the 250 could be worth
the extra money. If you are not having any trouble locating the objects, the 150 is probably OK.
I don't care too much about the ID as I tend to dig most everything, no matter what the ID.
But if you were using a large coil, the lack of a pinpoint mode could get frustrating trying to avoid
digging large holes. The smaller the coil, the less of a problem. IE: a sniper coil on a 150 would
be fairly easy. A 9x12 coil on a 150 could be a pain.. In that case, having a hand held pinpointer
would really be handy.
I don't think there is really too much difference between the two as far as depth capability.
BTW, the pinpoint mode is nothing more than a non motion mode that gives a continuous tone,
instead of the ID mode which requires motion, and is not continuous tone.