Upgrade to Maggi 3.7i or Tekton Moab?

@trebuchet

in my large room (20x18 with vaulted 18ft ceiling, leading into open kitchen) it just does not deliver the uumph that I am wanting when I want to "feel" the music hit me

As others have already said, in light of the above the answer to your dilemma is Moab, without a doubt! 
Your Parasound seems more than adequate to drive a pair of Moabs.

I had a similar dilemma recently. I ended up going from Magnepan 1.7s to 3.7is. The WAF was a consideration in my case, but it ended up being okay with her that I went with the bigger speakers. I was considering Martin Logans - the 11s I think it was - or Vandersteen Trio CTs (IF I could find them used and in good condition! You can find the Martin Logans used, the Trios, not so much.). Bottom line - I was too afraid that I'd spend more money for a downgrade in the sound that I prefer. I've auditioned Maggies against box speakers when I bought the 1.7's - I can't even remember the brands that they were - but there was no doubt that I preferred the sound of the Maggies over box speakers that were many times the Maggies' cost. I can tell you that the 3.7is are a big step up from the 1.7 - that true ribbon tweeter is sweet! The soundstage is bigger and deeper too. I am not unhappy, to say the least. It's probably endgame for me.

I have had Moabs for a couple of months now. Sold my 3.7i shortly after getting the Moabs.   Don't miss the Magnepans at all.  The Moabs are special.

I also have Eminent Technology LFT8b, which I feel are the equal or better than the Magnepan 3.7i.  So if you want to consider a less expensive option, I would strongly recommend the Eminent Technology over the Magnepan 3.7i.  

Prescribing a solution without a better idea of your tastes and music preferences is a common error on these pages.  Do you want more impact from acoustic live-to-2 channel ensembles (whether classical, folk or jazz) or EDM?  It makes a big difference.  Maggie 3.7is have plenty of "slam" for the former category, but not enough for the latter.  Classic rock sounds great on them too, up to a point.  Is that point enough for you?They are a whole nuther level above 1.7s, as said by others, and are a screaming value. But if you want to raise the dynamic ceiling up by a lot, you have to go with a big box big, cone area solution like the Tektons.  Also seek out an audition of McIntosh XR100s...more moolah, but in the same general design philosophy as the Tektons.  Much prettier, too.

Do you want more impact from acoustic live-to-2 channel ensembles (whether classical, folk or jazz) or EDM? It makes a big difference. Maggie 3.7is have plenty of "slam" for the former category, but not enough for the latter. Classic rock sounds great on them too, up to a point. Is that point enough for you?

@crusty Great questions. I will answer with a couple examples rather than try to describe. I have on my favorites these:

These sound great..
* classical (mostly Bach ranging from his organ works to orchestral and passions) - all these sound fabulous on my current setup
* piano jazz (e.g. Vince Guaraldi, Bill Evans) - sounds equally stellar

These I feel I need more.. (note this is with the sub engaged. The sub does add depth but does not satisfy the overall dynamics I am looking for)
* electronic/rock - Mutemath is a good example of this (they are hard to categorize so forgive me). Not enough live feel and kick here. Current setup does a 7/10 job.
* Electronic, e.g. Daft Punk Random Access Memories album. I’d say I am 7/10 on this one. 1.7’s do not handle the dynamics and Steely Dan type of funk well, at least not in my venue.
* Folk rock such as Delta by Mumford and Sons. Dynamics are not represented well here either, probably 6/10 rating.
* Biggest disappointment of it all comes with really dynamic soundtracks, such as Interstellar (Hans Zimmer) - I would give this 5/10 rating. There are several tracks on there with a very large dynamic range. No Time for Caution is a great example. This track I want to feel. If you have heard it you will know what I mean. It’s very emotional, very moving, it needs to be felt down deep and it needs to shock you. The feeling I get from the 1.7i’s on this track is that I have a compressor/limiter in the signal path :(. When the crescendo comes, I feel "is that it?".  I also know that I am at the upper limit of excursion on this track when it hits the peak, so there is a raw listening level issue as well.  I get it that this soundtrack has a ton of low-end and that is def not the specialty of planars. That is probably a large part of it