I've also recently just taken the step into an edgebander. My work hasn't required it often in the past and so I've not stuck my toe is this pond before. I have taken the root of buying a very 'good value' secondhand hot air bannder to get familiar with what I like about it and what I don't before investing in the 'real' machine. For me it's a good investment, I can play with it and work out what features I actually do want rather than get sold on by a brochure. At the end of the day, when it's time to make the 'real investment' the 'good value' machine will yield more than I paid for it either through eBay, this site or as a trade in.......although at the moment for what I do, it's slight limitations would nit justify an upgrade!
The hot air system is rather good I've found so far, and for what you describe as your needs Im not certain what additional advantages a hot melt system brings apart form consumable costs if your doing miles of the stuff.
So the things I've found so far!
Need a big heater for consistent temperature with a fast temperature sensor to avoid too much hysteresis in the temperature.
Getting the trimmers setup accurately is a pain. A course, fine and superfine adjustment is a good idea.
Preset angles of the blades is also nice as well as having variable angles. I seem to only use 8 degrees however.
The top and bottom trimmers need plenty of extraction,
Standard easily available Carbide replacement tips on the trimmers.
Siimply and easy access to the trimmers for cleaning pays big dividends. The removed edging sticks to everything and anything and affects the followers that ensure perfect alignment with the board being edged.
Powerful easily adjusted front and back trimmers. Knives that are easy to remove for sharpening / replacement.
Easily removable rollers for cleaning.
Cheap off the shelf bearings used in all of the rollers as they get full of glue after a short time and need replacing frequently to keep the machine working optimally. For me, ideally I would like a complete spare set of rollers and just swap them out every week providing the time to clean / replace bearings as necessary.
That's my list so far to compare any new machine against.
Machines are fairly simple, but are not easy to get to work optimally as already stated.