Contact form 7 is very basic and I've never had any issues with it.
CF7 is very solid and 100% compatible with Customizr.
However, as a newbie (it was the second plugin I ever installed), I found it quite daunting because it assumes, quite reasonably, that the user is HTML and CSS savvy. It creates plain forms and leaves any decoration to your CSS skills - unlike some other plugins which include styling options in their settings (mostly not to my taste though).
I have used it for three forms on my maiden site - including this long one.
