I think it depends on your listening habits.

If you lean towards more music I think you'd be happier with 5200's. If you lean towards movies you'd probably be happier with 3100 + Sub. That assumes you plan no further upgrades. Which we know is never true. You can always add a sub in the future to the 5200 setup. Where it would get more expensive to dump the 3100's and buy 5200's.

- Fiddler (IMHO)

If you think listening to music is fun, try learning an instrument.
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