I've tried several running apps on my iphone and the GPS fails on me, I've been toying with the idea of getting a garmin and my hand twitched over an eBay listing... I've now got a garmin!!
I ran yesterday with both monitoring, once again my IPhone could not find GPS, Nike + told me that I ran 4.92 miles the Garmin said 4.20 my parter asked me "whats the difference?" the difference to the average pace per mile is 9.46 To 11.16! I'm much slower than I thought! Oh well!
Your Garmin will let you down, but no where near as often 
love mine
I made the exact same change a few months ago. I started to go to my local Parkrun (5km runs) and the Nike+ ap was showing the distance at 5.2km or more. My Garmin 610 shows it between 4.9km to 5km, so it is more accurate. It has a lot more functionality too. But GPS technology is not infalible to we have to accept that the data is not 100% accurate.
I was finding it extremely frustrating that my Iphone would not get GPS, let me check....it picks it up and maps it 1 out of 5 runs, the rest it just shows my performance and guesses the rest! I am not hugely penikety about these things but I would expect it to be better than that!! I find the stats beneficial as I can study my progress. One of my Runkeeper runs told me I had done 28 miles, now that was a surprize as I was at the beginning of the programme and I had only actually run for 16 minutes!
Gwendolen is prone to exaggeration, especially on current pace. Very flattering but not much help. Does your Garmin do current pace?
When I first used the Garmin 610 I went overboard and had 3 screens set up with 4 fields in each. When I was running there was too much information and I couldn't take much of it in. I now run with only 2 pages. The first has 4 fields - avg pace, current pace, distance & time. The second page varies depending on the activity, but only has 2 fields.
The 610 is great but a bit pricey.
Thanks, Aftabs, I think current pace would probably be the single most useful piece of info after time and distance.
Current pace, yes, but then you get target pace and pace vs previous run, both very useful tools. If you're thinking of buying wait until the 220/620 are released then you might be able to get the 610 for a bargain.
I've got the fancy screen settings on my cycle garmin, yes, too much info first time out, having to flick between to satisfy the nerd in me. Now I have speed, distance, time, pace (can't recall whether that's current or average) and direction (not only a nerd but a map geek).
Thanks crox, do you know when that might be ?, said the tight wad.
Err, no, but they're advertising them on the site. Trying not to look, they have some tempting features 
My Garmin 110 only shows average pace but I find that's ok.
I have the forerunner 10, I have only used it once, I had time and distance showing but I had accidentally set it to pace, so I kept getting told off for going too slow! I was gob smacked when I downloaded it and saw all the info available.
Garmin
earphones and iPhone 
So...to garmin or not to garmin?
To Garmin or not too!!
iPhone 4s running app? Gps? 
