I got a sigelei 150watt tc and all I use to do is use rdas. I tried the tfv4 with the quad coils and don't plan on going back! It's great! I can't wait to try the octuple fused clapton coils. You won't be disappointed!
I do love my TFV4, used it on my Sig for a long time till I upgraded to the XCube II. Anyways, great tank for sure, however lately I've been hooked on my Haze Dripper Tank, just purer flavor. But, it's not a true tank with a 2ml capacity and isn't the best idea to throw it in a pocket/bag and go on with your day. It's somewhere between a dripper and a tank. Just thought it'd be worth mentioning because I stopped using my TFV4 mainly for that little guy.
Anyways, you asked for tips for tanks, wicking wicking wicking. If you're going to build your own stuff you really need to dial in your wicking process to prevent leaking. Nothing is worse than a tank draining into your pocket. Now, the alternative is you use premade coils but they aren't perfect and sometimes you get duds which sucks, plus they are relatively expensive (not really expensive but more so than wire/cotton).
I don't have a bunch of RTA's after I got my TFV4 and was looking for a new project once I nailed that down I ended up with the tank I mentioned before and have just been happily plodding along.
I'd answer one question, why are you looking into tanks? Is it just for more fiddling, or are you looking for something that's more convenient. If you're looking for convenience I'd suggest something with quality that has solid premade coils that are reasonably priced, The Crown tank comes to mind there. If you're looking to get your hands dirty and build your own stuff, Bellus/Crius/Griffin/VCMT seem to be the new big boys in town for the RTAs. TFV4 IMO is for someone who's in between. They want to do the RBA stuff, but want the freedom of popping a high quality premade coil in and just cruising. The replacement coils are more expensive, you drain juice/batteries, and it may not be the best of the best tank wise but it's a great tank with the best RBAs out there.