best way to measure speed/distance?

I've got a polar ft60 hrm with a GPS unit. It seems very sluggish, not working in woods and showing lots of wrong numbers. I can't trust its speed numbers and distances are way off the chart. I wonder if a calibrated foodpod is able to do a better job taking into account that I don't do speed intervals and my runs are done more or less at steady speed.

I tested both and found the footpod the most accurate. It can take a bit of tweaking to get the calibration just right, and will be best set up on a running track over several laps. I use neither device now since my running is made up of: more, less, faster, slower, rest and race. 

I don't rate GPS on account of the fact that due to lost and blocked signals innacuracies are guaranteed. Its a fact whether their fans like it or not. On a straight rosd, running in desert A to B over about 20 miles they will accurate to 10 metres. Twisting and turning routes in the woods and very built up areas will find out their inherent weakness. The signal is not the same as the one in your phone. 

As for footpods, I had a Timex SDM which has two problems, the first was the footpod weighing two ounces unbalanced the shoes, the other was that the on/off switch was on top of the device which meant that a heavy footstrike could actually switch the thing off. The switch should have been orientated 90 degrees to avoid this. The watch which came with this device was really good on its own, so I used this as a stopwatch until I accidently destroyed it when not realising it wasn't water proof went swimming with it on. 

I have a Garmin and normally use the GPS. It becomes useless in dense wood and built up areas due to lack of signal. I use the footpod in those circumstances.

On the running track I have a good signal, but due to the Curve of the track, Garmin is generally measuring 5% long. For pacing I use the footpod.

The footpod is only as good as the calibration. I have done this for track work, and separately for trail runs due to completely different pace, stride, shoe etc.

Footpods don't count strides, they work with computerised accelerometers which simply add up all the movements, fast, slow and indifferent. Linked to time these gadgets can calculate average speed and distance. Not sure why anyone would have to calibrate the things themselves since the manufacturer could do it but I guess this way you can eliminate any mistakes. As I said, they're not a pedometer, they are much more than that.

I've never had any problems with my GPS (Garmin Foretrex 301). I turn it on 5 minutes before I go out to give it a chance to pick up the satelites.

If you know people with GPS watches ask to borrow a couple of different ones and see if they perform any better than your current device.

I had a Garmin FR60 with footpod. The pod was excellent. Calibration is simple, it measured distances almost exactly the same as GPS but was much better at showing current pace. No mapping or other satellite functions, of course.

I sent it back because the watch kept misting up inside but if you're looking for an accurate footpod, the Garmin one is as good as they get.

Some Footpods do count strides. If you want cadence stats with Garmin, a footpod is required.

Where GPS signal is crap / non existent, the best GPS watch will not be reliable. Garmins can compensate by switching to footpod for distance. Current Pace can be provided by GPS or footpod based on settings. I have few problems in the my area unless I am in city areas where the GPS accuracy really drops. Then you notice some oddities.

Calibration? If you want accuracy then calibrate. Garmin footpod has a procedure for this, or there is a great bit if freeware on the web. Factory setting is 9% out on track, positioned on my current trainers. Was about 5% out with my previous shoes. calibration is not about correcting manufacturers 'mistakes' - it is calibration. Accelerometers are affected by pod location on the shoe. If I run on a treadmill (i have another shoe for indoors) - its a different calibration factor.

Read up on footpods, gps etc on http://www.dcrainmaker.com/

thanks for input, everyone, all the posts are really informative for me.