Any ideas on the Emotiva Xpa 1 Gen 2 vs other Mono or 2 channel amps?

Mancub, for the best in helpful advice, it is essential to also list what speakers you will be driving, and the room size as well.

That said, if Emotiva has any faults, it would be that they can get bright/harsh sounding with some program material, depending on the speakers.  The looks are also kind of plain.

Another option to put on the short list is the Vidar from Schiit Audio. If you employ two as monoblocks, they need XLR inputs.  The RCA jacks are only for 2 channel mode.  This amp was released last January and comes in silver or black.  

In monoblock form, it has 400 watts on tap, and the price per amp is $699.

No, that is not true, auxinput. First of all, what you are describing is true of almost any 2 channel amp that is bridgeable.  For instance, the  A21 Parasound amp you recommended states that in monoblock operation, the A21 should only be connected to a speaker that is not less than 8 ohms.  That's straight from the manual, and I owned the A21 for several years.

 You need to read up some more on the Vidar. They’ve torture tested it in monoblock form recently with Magnepan speakers, which are 4 ohms. The amps never shut down.  They are designed to be  fine at higher temps, but do have a shutdown function should they get too hot.  It's just another option, that's all.

Still, it would be good to know the room size and speakers being employed.

I just checked the specs on the emotiva XPA-1, and in the specifications section they state that 4 ohms is the minimum load recommended.  I guess not all monoblocks are the same.  

I wasn't suggesting that any stereo amps shouldn't be run in bridged mode, simply pointing out the A21's stated limitations.

And I tried to find the reference to running the Vidars in monoblock with the 4 ohms Magnepans, but can't find it.  I'd suggest that one call Schiit and discuss this if that's the goal.  But for sure it would be fine as a stereo amp, but then it's only 100 wpc.

Okay, here's another thought.  Adcom.  They've been introducing new 2 channel amps since 2011 or so, and the new amps are based on the award winning designs that put them on the map.

I'd suggest the GFA 565SE or the 575SE depending on how strong your back is.  Only the 575SE has a 12 volt trigger for automatic turn on, for some reason.