We've been using AmbuPro EMS for 10 years in my service, and it's made a major difference. It's easy to use and the front office folks can get bills out within a couple of hours of the call itself. When you're looking at ePCR you need to look at a few things:
1) Initial startup costs. How much will it cost for the software AND the hardware, plus any additional fees such as training, OT to train folks, etc.
1a) Hardware. iPads are great little devices (I have one, and you can take it away from me when you pry it from my cold, dead hands) but they aren't meant for the type of abuse seem in field use. I'm a Mac guy through-and-through, but when it comes to field use you need to look at real ruggedized hardware. One of the neighboring departments left their Panasonic ToughBook on the back bumper of their ambulance and drove 15 minutes to the hospital in a blizzard; when they got there they were able to open the ToughBook (amazingly it had stayed on the bumper) and continue working with no problems.
2) Ongoing fees. Most software has yearly support fees; make sure those are clearly stated and understood before you buy the "cheapest" and discover you're spending more on yearly support fees than on startup.
3) Architecture. How does this work? Are your runs stored locally and synchronized through a master server, or do you have to connect to the internet every time you want to access your web-based system? If you decide to change vendors later on, will you own your data or will it be sitting on someone else's server?
3a) Internet connectivity. If you have to connect to the internet every time you want to write a report you're going to have some major issues. You'll either have to write your runs out every time and type them in (a waste of time in my opinion) or depend on a cellular wireless card. The wireless cards are fine for consumers / folks who can afford to have the occasional loss of connectivity but not for emergency providers. Think of every time you haven't been able to get a cellular signal - you also won't have an internet connection. What then? Paper and pen? Why bother buying that system in the first place? Also, we are still expected to respond during hurricanes, blizzards, etc. - all times when cellular towers are known to fail.
4) Features. What are you trying to do with this? Are you looking for a way to "prettify" your runs, or do you want to be able to do faster / better QA, billing, etc. Are you required to submit info to the state? If so, does a particular system allow you to export directly or will you have to type everything into a separate state-run database? Again, why perform the same task twice?
5) Support / reputation. Talk to folks in the surrounding areas - what do they use? How do they like it? What kind of customer service history does the vendor have? Can you reach someone fairly quickly or do you have to chase after them for weeks at a time?
6) Integration. Will your ePCR product work with the hardware and software you already have? If you bill, can you export directly from your ePCR product or do you have to do that in a separate product (again, why duplicate effort?). Can you import data from your AEDs (You mentioned you were a BLS service - any plans to go ALS? If so, keep in mind that the big 3 monitor manufacturers all have some capability to send data to external sources.). How about CAD? Can the ePCR product you're looking at automatically import CAD from the system you already have (if appropriate) or are they going to try to make you change to a different CAD package?