Sounds odd to me. I wouldn't expect any tank surface condensate to last for long once the tank reached temp. The only way I could see actual surface condensate posing such a problem is in a humid room with the tank being rather cold to start and sitting like that for a day or two before any heating was done. (HJ's already well covered the flue gas condensate of a cold tank.)
Here's the problem: "condensate" in the insulation requires air movement to form, you need relatively humid air to come in contact with a surface at or below the dew point. But there isn't all that much water in any given volume of air that can condense, so it would take a lot of air flow in this very restricted space for that much condensate to form in the insulation. After the tank heats up the inside wall temp is WAY past the saturated air temp, so the water will begin vaporizing easily with any air movement. So if it were really "condensation" on the tank walls it would tend to remedy itself as quickly as it occurred.
Perhaps the installer leaked a lot of water into the insulation during the install... With little air flow in the insulation, it could take a while to dry out. Of course, some thread leaks or pin hole leaks in otherwise "good" vessels will seal themselves off as well, but are likely to bite you later.
However, I wouldn't put any faith in this being just condensate or installation water until I had carefully checked all fittings/projections off the tank to make sure none were leaking water. There are a number of threaded connections on tanks, and threaded connections are common sources of leaks.
Of course there could be a pinhole leak leak in a seam weld, etc. Since it is insulated and jacketed the only way to know is by deduction. If it keeps dripping from the insulation and you can't find a leak in any projections/connections, then an actual hole in the tank is likely and you will want a warranty replacement.
I'm assuming based on your description that this isn't a simple T&P valve drip (typically caused by the lack of a thermal expansion tank.)