I have 5 of the toptanks(4ml - 2.5 mlRBA) between hubby and me... they're pretty easy to deal with. the ssocc can be used in wattage. I like the .5 occ coils better(older 10-60w), but have used the 1.2(10-25w). I'm DTL so wasn't keen on the 1.2. I actually like the .5 claptons you can get(15-70w), excellent flavour and I've had complaints about too much haze lol. they can be MTL or DTL.
we also have two of the protank 4s (use all the same coils as the toptank 5ML -3.5mlRBA), larger and easier for me to fill with a side locking fill hole and most air at both base and driptip.
Kanger Protank-4 clearomizer
we also have two of the protank 4s (use all the same coils as the toptank 5ML -3.5mlRBA), larger and easier for me to fill with a side locking fill hole and most air at both base and driptip.
Kanger Protank-4 clearomizer