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If seriously I'd be tempted to save some money and go with the M400 even though I do think that the Matrix unit is in a league above the SMSL. One thing to be aware of that M400 has high output impedance so you'll need to be careful with amp pairing, but these Funk pres seem to have very high input impedance of 2MOhm? if this review is right, so shouldn't be an issue with what you have now.
The two are in totally different price categories. Performance is about the same, but the finishing on the Matrix is just ridiculously good it's not even funny.