The other rda dripping atties I have I am exceedingly fond of - but bear in mind I am a flavour rather than a cloud chaser.
I have a Delaniemods Aventador which I picked up in Spain. This one though unusual works brilliantly with a single coil 0.8 ohms but can accommodate up to 4
coils. Sadly now out of production - the maker only produces small batches.
On the more expensive side (£86.00 at current UK prices) is my personal favourite for size, build quality and flavour - the Origen 16 by Norbert. You can get clones cheaper.
And finally, possibly the bargain of the century, the tiny
smok 4 which is basic with a fixed drip tip. Small, cheap as chips (under £10.00) has knurled screws you can tighten by hand, looks like a wee steel bottle, is just about bomb proof in construction, runs happily,with a single coil at around one Ohm and is a flavour monster if taken slowly.
None of these leak and all are easy to work on. Not for everyone possibly, but I love them!