How are those Retro Duo systems?

[Yeti]

I'm kind of tempted to get one. They play SNES and NES cartridges. Supposedly there is a slight issue with sound in some NES games? Does anyone here have one that can tell me what it is like?

[Guybrush Threepwood]

Here's a review from Amazon about the NES sound issue:

I bought this more for the nes side hoping that it would work better than my side loading nes that is broken. First I am impressed by the concept and the top loading design. First game I threw at it was lifeforce for nes and it worked right away without blowing on it or reseting it. After playing for awhile I noticed that a lot of the sound effects were off. A lot of them were higher pitched and the music seemed to labor at times and even miss whole notes completly. The game itself seemed to work fine but I just couldnt get over the sound difference. Needless to say I returned it and I got a nes2 toploader off ebay for a little more. Still a good product but not for those who want a true nes replacement, there is no substitute. Great Idea but not quite there.

[demi]

Just use your PC or hack your Wii, Yeti. I can show you how if it's hackable.

... at least, I think you have a Wii

[Rman]

The problem with these systems is that they're reversed engineered, so you won't get 100 percent performance.