1.battery lasts about a day or less with very heavy use, standard use it lasts a few days (mainly stand by check email, sms, and maybe a couple calls ie minimal use) as with all smart phones tho if your using it all the time expect about a day
2. phone audio when in calls is bad (cause phone quality is low any way), the external speaker is good tho but it does lack bass but thats not surprising. one thing that is weird is its placement when on a table the sound is dampened alot cause it sits flat at the speaker point
3. GPS works fine from what i can tell (google maps only), there are other android nav apps but i have no reason to look for one so cant really comment
4. ummm its a phone ? the top edge can be sharp so if you press really hard to your ear your not gonna be comfortable. as for pocketability its very good one of the reasons i got it was because it was smaller than others on the market (albeit not by much)
5. ive had no real issues yet with the legend except the lack of internal space but this is a downfall of android as a platform. so ill have to wait for proper root for 1.31 before i can change this.