I am not that familiar with McCormack products although i have a lot of respect for what i've seen in terms of design.
As to the MI-3's, these sound different to me than the MI-2's. You will have to try them in your system and see if you like them. Personally, i like the MI-2's a little better. The 3's are a little more bottom heavy to me, which does not compliment my already "weighty" sounding speakers. However, given that you are running Thiel's, which many find to be somewhat bright, this might work perfectly for you. Either way, if you don't like the 3's, give the 2's a try. If you don't like the 3's nor the 2's, you don't like Goertz products then. : )
Good luck and i hope they work well for you : ) Sean
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