I've now spent a few days with the Griffin 25...bare in mind I didn't/don't own the original Griffin.
All in all, a decent tank for the price (£25!), decent deck space, top fill, juice control, velocity deck, plenty of airflow. A good handful of negatives as well...
QC mostly, I took mine apart straight out of the box to be greeted by black/brown stuff around the threads on the inside of the chimney section - machine oil, machine oil is so rare to see on an RTA/RDA these days that even clones come clean - poor form.
Threading, is, rough. Wick ring takes the patience of a saint to get on straight, top cap feels like its grinding over the first few threads too, non of the threads feel what I would call smooth, the manufacturer needs to change out the dies more often, looking closely they're just blunt threads cut with a blunt die (I do a fair bit of work with threading equipment).
Final negative is the provided allen key, its one of the 3-in-1 jobs like what Wotofo have been putting out lately, its bloody awful to use, far too small and not very ergonomic. If you plan to buy this tank treat your self to a regular 2.5mm allen key.
This tanks main rival (IMO) is the Aromamizer Supreme, its healthy competition, the griffin kicks out bigger clouds at the sacrifice of flavor, while the supreme feels a more premium product, the price difference isn't massive at the moment, I've seen the supreme for £34, so £9 in difference. You can't really go wrong with either but if I were to choose one it would be the supreme
A little note on wicking if anyone is struggling with it, the 25 has a near identical layout to the Cthulhu V2 deck, put the wick ring on first, build, then just rest the wicks at the top of the juice channels, if you put the ring on afterwards you risk choking the cotton