I have owned several Stihl Backpack Blowers (BR320's & BR400's, if I remember correctly), never had any problems with them, they all started within 3-5 pulls, usually. I used them commercially (landscape/lawn care) and had numerous operators of all shapes/sizes no one really complained about the comfort of using them and the blowers tolerated the commercial use easily.
I haven't had any experience with the edgers (stick edgers, I assume). If they have the same engines as the FS85's or FS90's- you should many years of trouble free service- if you do regular maintenance on them. We used straight shaft trimmers with the twin line heads (turn the complete unit so the lines are horizontal to the desired edge) to edge with and perform the regular string trimming duties. If the edges haven't been edged-ever, the string trimmer will not make it look nice, unless you continue to edge every week, then I would use a manual hand edger, initially and then keep it maintained with the string trimmer.
Good Luck!!