I'm actually using one right now. When I get back to my pc ill type up something more substantial.
So, back to the PC! In short, I like it. Whether or not you like it will depend on why you don't like the protank. if you don't like the airy draw, use EVOD coils, it tightens it right up. If you don't like the look, the IKV fixes it. I think it looks great, especially with the included drip tip. It is a little long, and if you're using an 18350 size mod or an ego battery it will look a little off, just like it would on an eGO type battery. But it looks great on 18650 size mods. My wife and I use them on Provaris, my brother and sister use them on the VAMO. No air flow problems due to cut channels in the bottom cap, so you can flush mount to your hearts content. The glass seems nice and solid, and has survived all my inadvertent drop tests(wood, linoleum, tile).
In closing, if the protank performance is bothering you in a way that EVOD coils won't fix, don't buy. If the EVOD coils will fix it, but you're not a fan of the protank look, the IKV is the way to go. Highly recommend, and I actually have 2 more on order since I like them so much.
Happy vaping!