If you are thinking of buying the FC40 then join this Facebook Group, great bunch and will answer any questions you have on this model
https://www.facebook.com/groups/1493623280865016/ :)
Check out my Drone Flyers site http://droneflyers.wordpress.com
There are some great Quadcopter Reviews. Of the models you mentioned the FC40 is the best choice.
Tend to rise and fall yes. My son-in-law a competent Heli flyer can pick any of my micro Quadcopters Hubsan X4 , Ladybird V2 and with a few seconds trimming can get them all to remain at a fixed altitude indoors and out. I've seen him put the remote down for a few seconds. I struggle with Helis...
Check out some great Quadcopter Flying Tips I'm sure these will help
http://thebestquadcopterreviews.com/quadcopter-flying-tips/
Once you get used to the sticks you shouldn't have any problems, try just lifting it up and down gently. The Hubsan X4 H107C HD is a great little flyer.
Great choice, get 5x500 mAh Batteries and make sure you get rechargeables for the transmitter
http://goo.gl/WqyMvt
and a crash pack
http://goo.gl/toQQOS
Micro SDHC class6 2-16G
No model confusion
Hubsan X4 H107L No Camera
Hubsan X4 H107C ( Camera version .3 Mp )
Hubsan X4 H107C HD ( Camera version 2.MP )
Hubsan X H107D FPV Version
The Hubsan X4 PRO H109S is a far bigger Quadcopter that has not been released
I have posted a Flying Tip and Hint sheet here
http://thebestquadcopterreviews.com/quadcopter-flying-tips/
Any suggestions most welcomed
You can also see some great Quadcopter Reviews
http://droneflyers.wordpress.com