Hi there.
I have both watches ZGPAX S5 & Z1/ROCK.
Here's quick feedback about these both watches.
First when you got them on your wristle the  Z1 looks more bulky than ZGPAX and ZGPAX  look more elegant and more near of a watch than the Z1. so you don't feel it but honestly after using both . You don't really mind about witch is little bit more bulky or not both are good. About the lock screen  both give you time one in android lock screen way (Z1) and another with analogue watch but is is not locked.
 
About the camera I won't speak about quality but about their position. On the Z1 it is place on the side so you can easily take picture but you can not use skype for video-conference. On the ZGPAX it is in the front so you can easily make video-conference via skype but it is difficult to take picture. About skype on the Z1 you have to install it. On the ZGPAX the native one is buggy so you have to install it via google play and disable the naive one (skype). Well good new for an Asian product google play is native no need to do do some "bricolage" for getting it working.
 About the screen here there no mystery the Z1 is more easy to use because the scree is about 1.3 more longer, but the ZGPAX's screen looks more bright and clear. And it don't give feeling that the screen will die soon. People using the Z1 know what I'm talking about.  
About the keyboard, well for those using the Z1's native keyboard they know already it is a punishment to use it. It is  same level on the ZGPAX. I expeted it was more horrible but no it is same. But there is a different, the Z1 allows using a bluetooth keyboard (I use my Nokia N900 for this purpose) but ZGPAX not. There is no native apps for this in the ZGPAX, so if some one find a free app..Let's us knowing.
Another point the Z1 have a true android desktop so you can put on the screen widgets icons ect... the ZGPAX not it has a proprietary (manufacturing) interface so say bye bye to widget ect... and hello to 4 square icons/screen. For example if you need a weather widget, on the Z1 it is easy but on the ZGPAX you must put an application's icon on witch you click for getting the weather's programme open... unless you put the ADW launcher and follow the xda forum's method.
About connectivity I don't use all on the ZGPAX but I can say about wifi. If you compare ZGPAX and Z1, ZGPAX's wifi works marvellously every one know it is not case on the Z1. My problem, on the Z1, was solved when french "free mobile" allow 50Mb data plan without any charge. It is for free I pay 0€ for all (2H phone sms and 50Mb data plan). This allow me to update weather, calendar and mail via GPRS and not wifi.
There is a micro USB on the ZGPAX for charging battery, connect to PC and hearphone, yes hearphone is connected via micro USB and used for FM radio.
Here are some links about ZGPAX:
http://forum.xda-developers.com/showthread.php?s=f07e947f33c431772097af40842bace 5&t=2575556http://forum.xda-developers.com/showthread.php?s=f07e947f33c431772097af40842bace5&t=2575556
 
and  
http://forum.xda-developers.com/showthread.php?t=2507033&page=8