It is not much different if you were performing as an EMT should. I see many EMTs in my area, that basically just pick up a patient and drop them off. Many lie about vitals or just document that a patient refused vitals. The treat it as a taxi ride. If you are actually assessing your patients, obtaining histories, talking about medical conditions, then it is easier.
I work both IFT and 911. I can tell you that many times in an 911 setting, you do not know what is really causing the issue and sometimes requires more critical thinking. In IFT, the patient typically already has a diagnosis. You also have to think about extrication of patient's from certain residences/facilities. Most IFT comes from a hospital bed to hospital bed. Please do not mistake anything that I said. Sometimes there are critical situations and awkward extrications in IFT.
I personally started in a 911 settinging, volunteering. I did not get into IFT until about 2 years in. It was a change and there were things that with IFT are very different. For example, you are not usually taking patients into residences in 911, sometimes the reverse is different. You also may deal with nursing facilities and hospitals more often, if you do not have many in your local area. Its a new world at times.