The Kangertech Squareone (or Kanger S1 as I've seen it in some places), is a relatively new entry to the eCig market, or at least new to me. I had a chance to briefly use this eCig when I ordered it for a family friend who wanted to quit smoking the same way I did, but they didn't want to pay over $60 for their kit. So I found a retailer here that sells the starter kit for $49.99.
In terms of vapor output, it is also on par with the eGo it seems.
It does have its downsides though. One slight annoyance is the fact that the thread that connects the tank to the battery is made of plastic, so if you over-tighten it the plastic threading will break and the tank will be unusable. Luckily it, like most eCig kits, included two of the tanks. But it is still an annoyance nonetheless.
Overall it is a pretty decent product, another good one for starters or someone looking to purchase a backup in case their main unit breaks.