SATNAMSCOTT  I`ve had the SRS iWOW product for itunes on my Apple macs for several years now.

Versions 1 through 3 have all performed as promoted.

In my estimation, Version 3 (when compared to V2) offers moderate improvements in definition/separation, better overall balance, in general a crisper, more clear, less "over driven" tone.

I did prefer the version 2 window (the curious "wave/pulse" graphic aside) to the current one.

With respect to the purchase itself I had no issues, no reason whatsoever to complain. The download/upgrade ($6.00) worked fine right from the start.

btw. My current/main mac setup is as follows:

1 year old i-mac (2.8 duo)

w. re-tread (local garage sale purchase for $10.00) JBL "Creatures"

For me, the iWOW plug-in has really made all the difference.  
(Version 3.0)