Hi Gary
The Prowler has a superb reputation and, like others have already said, would be an excellent tool for you.
This may sound initially silly, but worth consideration. You say you want to leave carpets drier. Have you looked at your wand technique? I so often come across tecs with a porty who use a technique more appropriate to a TM use. I even spoke recently to a highly respected TM user who needed to use a high performance porty for access reasons and later admitted that the carpet was too slow drying because he forgot to adapt his wand technique!
Another reason for upgrade you state as being ease of use. Where is your prime domeatic marketplace? High rise buildings in particular may have access problems, so think about it carefully.
If you are looking to expand your commercial work, what sort? Pubs, restaurants and so on leaves you with one choice of machine: A truckmount. But offices, health centres and the like may give you an option of going LM.
Best advice before you spend a penny of your hard earnt is to WRITE DOWN a detailed business plan of where you want to go during, say, the next five years, then you can prioritise your investments.
Safe and happy cleaning
The Ken