Just a few thoughts on my personal experience working with MA's....
I worked in an allergy office for seven years. I was the only nurse that whole time; the rest were MA's. The one that trained me had been there a couple of years and she knew the skills of her job to a T, but not necessarily the theory and physiology behind them. She would hang and run gammaglobulin infusions that I wouldn't touch with a 10-foot pole since I didn't have any IV certs. I'm happy to say she went on to nursing school. She certainly had the aptitude for it!
I was also amazed that MA's were giving allergy shots. As an LPN in my prior job, I wasn't allowed to give them; the RN in the clinic had to.
Every MA that entered the allergy practice was expected to give allergy shots. And if the allergist didn't have that much confidence in them, they were put in the front office.
He always advertised for MA's when he needed to hire; I'm sure it was a cost of labor issue. The only reason I got hired was because I happened to send him an unsolicited resume, had previous allergy experience and was interested in learning more.
I've never had a problem working alongside MA's. Our background training was different, but I never noticed a real difference in job performance. Some were better than others, just like in everything. In fact, they knew things that I'd never had training in, like venipuncture and administration.
I'm currently looking for another specialty office job and expect that if I get one, I'll again be the only nurse there! Most of the offices around here prefer MA's because that's what they're trained for. If I can't find an office job that sounds interesting, I'm also considering returning to my roots and doing LTC or home health. I don't expect to run into any MA's there, however.