Differences in the G3 and G3plus series amps

[madh4ttr]

I bought the RG75 G3 combo in early 2007, love the amp, and for about $350, it's a steal. Then I see the same amp and it is the G3plus. From everything I have read from the literature on both amps, I can't really see any differences. THey both say the same thing about the circuitry, blah, blah, blah. I noticed instead of the contour knob that are on the G3's, it looks like the knob on the G3plus' amps are presence. I would like to know what is so different about them. Also, the price difference between the RG75 G3 and the RG75 G3plus is about $100 difference.