There is an option in LW settings to allow to be informed of updates. Also, if you bookmark your Personal Pro Download page & you know you are getting near then end of your 6 months, they will offer a small discount for continueing. At least I presume they are still doing this. And recently they offered the option of 12 months for just an extra US $10.

Pro gives connections to more Ultrapeers. Allows downloads from more peers per file. And has a better search function for the rarer files (can reach further into the network.) But that won't be noticed when searching for common files. Of course there's also not that annoying upgrade window that Basic users get when opening LW.