Polk Audio LSi15(used) vs Polk Audio RTi7 (new)


I’m looking for a pair of floor speakers to compliment my Polk Audio TSi500’s used for surrounds,a Polk Audio ai6 center and a Polk Audio HTS10 sub.  They will be powered by a McIntosh MC7205 amp, McIntosh MX-136 pre an Oppo 103D for sacd and a BlueSound Node 2i streamer and Morrow Audio cables.  I like the LSi15’s because they are 4ohm and that will increase my amps power from 120/ch to 200w/ch for those speaker and from what I’ve read so far, the LSi15’s are much higher ratings.  The seller said there is, “Absolutely no issues with the speakers.” And they were rarely used.  The cabinets have many small nicks and scratches, but I want them for their sound. The RTi’s are brand new, they have gotten very good ratings also.  I haven’t heard either speak yet, so if anyone has, I welcome any recommendations, thanks 
cody57
I also have a Audio Technica LP-120-at usb turntable which should sound good with the front towers.
I have the polk lsim707 sound fantastic.Got them in Jan.for 1400 they were returns that's with shipping  and taxs.
That’s A Good Price And I’ll bet they sound terrific!!  I’m upgrading most of my equipment to Mc’s and speakers so, my budget is pretty slim, thus the used speakers or the great price of the RTi’s. I want to get the best I can afford.
I've always read it's best to match your fronts with your center.
So I don't think the LSis would be a good match.

I would do some research on how important it is to match fronts
with center before deciding.
Thanks vinylvin, I found a great deal from Polk audio on a pair of RTi A9’s that will match my RTi A6 center speaker. Thanks. I’ll rate them when I get them and broken in.