Does anybody here use these? Is it worth the $150 for a toy? I'm thinking it would be nice to find out how many feet I climbed. Distance, speed and all the rest I get off my cateye.

Does anybody here use these? Is it worth the $150 for a toy? I'm thinking it would be nice to find out how many feet I climbed. Distance, speed and all the rest I get off my cateye.
Detailed comments below. Short and sweet: GPS is a fun toy, but not worth it just for altitude. Unless I'm out of town, riding somewhere unfamiliar, I leave the GPS at home.

I use a Foretrex 201, which is similar to the Forerunner, but has more in the way of mapping/tracking features instead of exercise and running features. I don't think the unit would be worth it just for the altitude. For one thing, if you're riding in decently hilly or mountainous terrain, it will lose its lock on the satellites when you're going up or down valleys. Just to give you a sense of how fussy this can be, in the local city park, where the valleys are no more than 300 feet below the hilltops, I often lose satellite lock while riding or hiking on the steeper hills. All it takes is some moderately small hills blocking your view of the horizon in a couple of directions or even just a lot of tree cover.

What I like about having a GPS for cycling is that when I'm out of town with my bike I like to explore---ride way out into the country, just following whatever road looks interesting and the GPS lets me know how to get back home and lets me keep track of how far I've gone so I don't end up out of ATP and 50 miles from home. It's also nice to be able to download a map of where I've been so I can go back there if I liked the ride. The Forerunner is rechargeable and runs for about 14 hours on a full charge, so I don't have to worry about losing power during my ride unless I get into the super-randonneur level (as if!).

The Foretrex has lots of bells and whistles. You can display your speed, compass bearing, altitude, vertical speed, and many more data in lots of different modes. You can program waypoints and directions if you're taking a trip in an unfamiliar area.

Also, if you're into logging all the gory details, Garmin has a very clean and functional computer interface, so I've never had a problem downloading trip data to my computer.

All in all, it's a fun toy, but because of the sometimes-flaky signal, for altitude tracking I use my cyclocomputer (Polar S720), which has a barometric altitude sensor. It's not the most accurate thing in the world because it can be fooled by passing weather systems, but since I tend to go inside if I see a supercell developing, the barometer is good enough for me, so I leave the GPS at home. The barometric sensor gives me decently consistent altitude records on different days, so it's accurate enough for my purposes.

As Fredke said the Altitude is not quite as accurate as you might wish. But it can come very close. It helps to know what the altitude is where you start(each time)) for calibration purposes. if you go to either USGS site: http://nmviewogc.cr.usgs.gov/viewer.htm (the national map viewer) or http://seamless.usgs.gov/ (USGS Seamless Data Distribution System) you can nail specific (waypoints) data point after your ride.

The Altitude accuracy suffers because of the physical model used in the gps. Your planar position (Latt & Long) will be w/in 3 meters (best case). but again altitude will vary on the gps for the same route repeated. Don't not get the toy, it is rather nifty & you can also use it for the sport(?) of Geo-chaching (hi-tech dependentant orienteering).

I have a Geko 301 w/a handlebar mount. I think it's tons of fun for checking my progress & times between established waypoints FWIW.

As I mentioned before,when you establish a waypoint, plug those coords into the USGS sites & find the real altitude, use that to correct wour waypoint & off yo go....

P.S. A gps is a real good way to calibrate your cyclocomputer & car speedo!