I use to work for Armstrong, I noticed a lot of people at Lifeline jumped ship and appear to have started Lifeline. I worked at Armstrong from 98-02, left after getting my medic (went to Western Mass). When I left moral was low. Some of those who left Armstrong were blamed for the moral by employees. It could have come from above. I will say I did have a lot of fun working there at times.
I would be cautious of a start up service. It sounds like a lot of money must have been spent to start Lifeline, I would like to know where it came from and how many contracts they have already arranged.
If you had a good time at Pro try them. When it comes down to it all depends on what you make of it. Don't do anything stupid and you can always change companies.