The studio I work at has wacom cintiqs and having gotten used to them, I can no longer go back. This is probably the best scenario where you use the cheaper tools to get you into the industry and then make money to afford the higher end ones.
Trying to work on the yiynova m19 (the older model) now is like drawing through a window. The glass is really thick and the pen sensitivity is a bit clunky but good enough.
I would definitely suggest it for super poor people that are unemployed and looking to get into the industry. You can make it work. It is possible that the newer yiynovas are better. They are steadily fixing problems from the older models and software is always available for you online.
I have now sold my yiynova for a very low price to someone who needed it. I'm pretty sure they'll be getting rid of it one day for the exact same reason.