Rotel RB 1070 from Elite Receiver Big Difference?

I'm planning on a new set of speakers (Posiibly Polk LSi9's) that will require 4 ohm amp. My Pioneer Elite receiver (43tx) only rated for 6ohm or higher. Although the Pioneer sounds good (very neutral--which is its job), I'm thinking of Rotel RB 1070 to drive fronts (then I can upgrade speakers). I hear Rotel sounds a touch warmer than Pioneer? If this is so...that would be perfect. Anyway, I'm hoping the Rotel amp would be an improvement or as good as the Elite amp. Opinions?
The ONLY hangup with the RB-1070 is no factory 4ohm rating.
8ohm, sure and 'bridged' also, but no 4ohm rating.
It is 130x2@8 and (can't recall) 330 or 360 bridged/mono.

That being said, unless the Polks are really awful loads, you should be OK. The Rotel drove my Magnepan MG-1.6s quite well, except when going for sheer loudness and never ran too warm... The Maggies, while being 'current hogs' also are not a bad load, NEVER going below 4ohms and with moderate phase angles.

The RB-1080 is 200x2@8 and HAS factory 4ohm rating.

Maybe it is worth the extra (aprox)40% new?
2 further points.
What is the mininum impedence of the Polks?
Do you want to take a chance on having to do this twice?
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I recently upgraded from the Rotel spearates to the Pioneer Elite receiver. I don't use it for music, just movies. In my system, to my ears, the Elite was just as good, and, perhaps, a bit more detailed, and a tad quieter. I would agree that the Rotel set up was warmer. The soundstage was a little wider but the Elite is definately more transparent. I am considering hooking up the Rotel 6 channel apm to the Elite pre-outs to see what it does, but not in a hurry as I'm pretty happy with it. The new audio codecs are simply amazing, which the Rotel gear, obviously, doesn't do. I think it's the RMB 1068 pre/pro.