Oh yeah, if I'd found ECF before I got my first pv it would have been an ego. It's fat cigar size for the 650mAh and a ton of options for it. It's barely longer than the volt (with no cart on they are the same length http://img.photobucket.com/albums/v233/leftfeild/capoff.jpg ).The ego is a cheap and inexpensive way to start vaping.
My mom and I started vaping at the same time. I started with a $30 ego that I'm still using. Never used carts in my life just cartomizers. My mom went the 'want to look like a cig' route. Started with a Smoke Tip, then a V4L KR808, then a Riva Ego.
We ended up at the same place but it took her about $200 more to get there.
She still uses the KR808 from time to time because she has money invested in all the stuff she bought. I've gotten her a Bloog battery, bloog cartos, volt battery and volt cartos and they're all pretty much the same. You'll get a decent vape. To me you get a better vape with a 510 (battery life sucks though) and the best vape with an ego.
She's in her 70's with health & vision issues so if it's not too complex for her, I doubt if it's complex for anyone. She was able to adapt to something that doesn't resemble a cig the first time she vaped an ego.
It was never an issue for me. I never thought there was anything particularly attractive about smoking that I'd want to emulate that with a pv, I just wanted to find something that would get me off cigarettes.
It's mainly because the op asked for something cig size that feels like a cig that the volt would be the best performing cig replica. It's a cheap starting kit to test the water out with that's not a throw away. I still use mine because hands free vaping is a neccessity sometimes and I can't do that with any of my other pvs. They might stick to it, they might want to move up in battery life.
For what they asked for, 510 or volt/bloog/halo. Just to me a volt style is better than a 510 for ease of use and power for size.