Hi, I don’t have much experience in this area, but I usually choose a tank considering a few aspects.
Does it fit my mod? I check its dimensions, that’s obvious. The price, what I am willing to spend on it. What I watch the most is the airflow. How restrictive it is. It depends on what one likes. For example, it’s important to me that it can handle 2.5-3 mm. If it can only do smaller than that, I won’t even buy it. But many people like restricted airflow, so this is completely individual. Then I inform myself about it from several different sources. I watch several videos about the chosen victim and if the reviews are unanimously good, then it’s a candidate. Here too, I usually read the experiences; many people have already written about many things, based on this one can get informed.
There are MTL tanks that receive unanimously good reviews. These are definitely worth looking into.
I am not particularly bothered if the airflow is not adjustable externally, provided I can find the perfectly sized airpin for it. In many cases, several different ones are included; the more, the better, so after some experimentation, one can find the most comfortable one.
Generally speaking, I prefer top-fillers, but there are exceptions where I can easily overlook that if the flavors and other attributes compensate for some inconvenience.
I won’t mention specific ones because in the end, it comes down to trial and error. 
What appeals to you and meets your expectations.