There is full support and there is full support. Personally, I would take the "support" offered by the users here. Once you get AC working, there is no reason you have to jump in all at once.
Tech support for AC are not there to make money. You pay an annual fee, but you do not have to. Some EMR companies FORCE you to pay for support during the "Go Live" stage, which John has already commented on.
Some of these other EMRs do have a two to three month learning curve. I watched it over and over with practices here.
One thing about AC is the progress note is so simple. You could start there for a month. Then add ePrescribe, then add orders. It's a lot like Word, you start with opening it and writing a letter and saving it. Maybe 1% of the product. I still use only 5% of the product, and I have never had to call Microsoft as I would if I tried to use the entire program.