It's more than a year since this thread started and the game has moved on.
IMHO the best bang for your buck thermal scope is the WT series sold by Night Vision Store (Clive Ward)
http://www.nightvisionstore.co.uk/PBSCCatalog.asp?CatID=2376122
I have no association with this company but I did buy a thermal scope directly from China before NVS started selling the same model here and over the last year I've spent a lot of time researching thermal riflescopes and shooting with them
The Pulsar Apex scopes uses a 25 micron core with 384x288 pixels
The WT1 scopes use 17 micron cores and are available in both 384x288 pixels and 640x480 pixels
Comparing directly between the Pulsar Apex 75 and the WT1-75-3, both have 75mm objective lenses and 384x288 pixel cores.
The smaller pixel pitch on the WT1 scopes results in a physically smaller sensor which results in a higher base (optical) magnification and hence a longer detection range
Magnification on the Pulsar Apex is x3 (optical) and x2 digital giving a maximum magnification of x6
Magnification on the WT1 is x6 (optical) and x2 and x4 digital giving magnifications of x12 and x24
Other advantages of the WT1 over the Apex is that the WT1 uses an f1 objective lens lens while the Apex uses an f1.4 objective lens. This means that the WT1 admits double the heat of the Apex making it more sensitive to small changes in temperature by a factor of 1.4
Finally, the OLED display on the WT1 has a resolution of 800x600 while on the Apex it's 640x480 - having looked through both there's no doubt the image on the WT1 is noticeably better than on the Apex.
Price wise the WT1 is £3750 and the best price I can find for the Apex is £3589
IMHO the WT1 is well worth the extra.
Once again, let me stress that this is not a sales pitch for Night Vision Store products (I think Starlight are selling the same scopes under their "Icarus" brand), but simply an attempt to help people who might be thinking about spending a lot of money to buy a thermal riflescope to make an informed choice.
Cheers
Bruce