The Eleaf Lemo seems to be popular right now, I just got one and love it. Everything from the pyrex tank to the adjustable airflow but it's my first rebuildable so I have nothing to compare it to but it suits me best for the way I'm using it.
When I first got it I was using it on a non variable voltage evod battery (3.7 volts I think), don't know the mAh's but it's the smallest ego styled evod battery you can get I think (came with one of the starter kits a year back) and it worked okay.. It does take about 5 seconds to heat up at the beginning of a session though, and the battery life isn't great. I think the ohms of the coil was around 1.8-2.2.
I think to get the best experience out of a rebuildable tank you should get a better battery/mod.
Last week I got a DNA 30 clone from focalecig.com for around $40 and a Sony VTC5 battery to go with it off ebay and I'm a lot happier.
Even if I upgraded to a better ego styled battery I know I wouldn't have been as happy because they only go up to 4.8 volts and my DNA 30 my sweet spot is higher than that, like to be able to pinpoint the wattage for different coil builds and juices and it's nice having a LCD screen to see how much battery you have left instead of going buy estimate or LED lights too.
Just warning though if you do get one of those DNA 30 clones, make sure you put the battery in the right way or it could fry it.