This is an interesting thread in that lately I've been testing one of those services that
allows you to use a gps enabled cell phone as a fitness gps.
The advantages of the Garmin units is that they update GPS position much more often
than the particular cell phone I have - mine updates its position every 5 seconds (Razr
v3m) and the newer ones do it ever 2.5 seconds but I believe the Garmin units do it
even more often but a 305 owner should be able to clear that up.
The disadvantages of reading speed every 5 seconds at 20 miles an hour will really
do a number on distance at times. Especially if your course changes rapidly at
high speed. The computer sometimes "cuts off" parts of where you rode if you
encounter that kind of thing.
See:
http://bimactive.com/ba/journal/post/4941/5383
This is a ride I did last weekend.
Look at the left side of the pic about halfway down where it says
"E Bush Lake Road". Just below that you'll see my GPS track looks
like I rode right thru the lake!
That is a downhill so I curved around that area but was at least
a ways away from the lake. GPS said 19.21 miles but my bike
computer reported 20.5 when I was done - so it's not completely
ideal but they corroborate altitude changes with known USGS data
for the area so it should be more correct than GPS data alone.
Would I get a 305 if I had the $? Yes. Will I keep using the service
I'm using with my phone? Also yes since I don't have a 305 and it's
nice to be able to save maps of where I've ridden for google earth
access so my wife can see where I've ridden.
Will I upgrade my phone to a faster reading phone? Yes, eventually.
The KRZR and some other newer phones are 2 to 2.5 seconds reading.
But if the $ came my way, you can bet I'd get a 305.