Would MA5300 Integrated be Worthwhile Upgrade

I currently have a Marantz SR 7008 AVR where I'm using the preouts along with a Rotel 1582 II.  Speakers are Martin Logan Motion 40's.  I am also using a Martin Logan Sub with this setup. This system sounds pretty good.  Many commentators criticize the sound of AVRs but the preamp section of the Marantz provides good detail and separation and seem to process the digital signals from my Sonos Connect fairly well. The Rotel has 200 WPC which drive Motion 40's well.  Because my room sucks I have the speakers set to "small" on the AVR and having to use a high cross-over pushing more of the bass to the Sub.  If I run the speakers on large without the sub,  the bass is boomy and sounds terrible.  I've always dreamed of owing a Mcintosh amp and wonder what I'm missing.  I heard the MA5300 at Magnolia playing with the Motion 40's.  It sounded really sweet, the soundstage was unbelievable.  However it's very hard to tell if its Magnolia's acoustically perfect room that made the combo sound so sweet or if it was the McIntosh.  The Mc is $5,000 and only 100 wpc and my Rotel Amp is 200 wpc.  Is it possible for the lower watt Mc to outperform my current setup all else being equal.  Am I likely to have a noticeable improvements ?  Also I never owned an integrated and wonder if there is a setting to run the front speakers as small for use with the Sub?  Thoughts appreciated.