DRDUL I use myTracks because it offers two features that I haven't found in any other app:
I can edit GPX tracks. I have started to use a GPS logger to geocode photos, but find that in the city with tall buildings all around, it sometimes"drifts" by 10 or 20 metres from my actual position. Rather not geocode a photo with an erroneous location, I can edit the track before geocoding. My only request is the ability to edit multiple points at once, rather than one-by-one.
I can determine where I was at a specific time, and I can determine what time I was at a specific point. And I can do this from the raw GPX data, without having to convert to KML and use Google Earth (which doesn't work as well as myTracks for this purpose, anyway). My only request (and it may be a limitation of Google Maps) is a higher zoom level so I can see more details.
(Version 1.6dev4)