Well, I suppose I should follow up too... I went Wireless..... and I LOVE it!
When I upgraded to the Z4, I added 6 triggers and the MIDIjet Pro wireless app as pictured above. It is fabulous. I run a TD-10, and have not had any trouble using the wired app as well, but I won't go back to that unless I have a catastrophic failure of the MIDIjet... argh! I shudder at the thought, LOL!
I am using the 9 volt Li-Polymer 520mAh IPowerUS batteries, all rechargable, as recommended by Dave. They are not cheap... 4 batteries and a charger for around $100. BUT... I have one battery I use, and another as a backup all charged. I haven't even opened the other two yet, nor do I see a need for them in the near future. I have "tested" the battery staying power. I used one battery for home practice for about 3 hours, then at a show for 4 hours and I left the zendrum on the entire time), then at a band practice, where it finally gave out after about 2 more hours. I would say you can easily play a gig with a fully charged battery and have no worries.