Meaning two things; I wouldn't trust any pro offered on the network. Secondly, are you really so miserly as to not buy pro if you really want it.

It's not as though it is a US1,000 dollar program ... it costs around $20 lol.

How many big macs can you buy for that. Not too many. lol
Why do you think they label it a free upgrade ... whomever it is really wants someone to be 'tricked'. Probably has spyware inside that explores all your private details on your computer & sends it back to them; phisher or back door to give them access which your anti-spyware, firewalls, etc. would not have a clue about.
A program like BearShare introduced something that the gnutella community was in uproar about. It was taken out, however the new owners of the program have apparently reintroduced it. It gives the owners some control over the program itself. Like a switch. Not many of today's B.S. users know about it.