Look at this article on the GBS-100 laser : http://holographyforum.org/phpBB2/vi...05c63031b28cc1
They don't speek of coherent length on the eBay page of the GBS-100, but in this article they speak of 12 feet, very good for holography But it has no TEC cooling, not a good point.
To get full power of this laser : turn it on, and if the power is half, turn it off, wait 30 seconds, and turn it on again. Try it 3-4 times if this doesn't works immediately...