Higher powered but efficient amp with the imaging of a Pass XA-25?

I agree with @ghdprentice . You are all over the map You have gone from 25wpc to 250wpc and from 97db floor standers to 85db bookshelf speakers. You are trying to fill a big room but that won't be done with bookshelf speakers. Changing amps isn't going to change that fact.

I too have a big room which is also my LR, & DR which is 15 x 32. I fill it with a 65wpc Don Sachs Kootenay and Silverline speakers with subs..Before that an ST-70 w/ 35wpc.  FWIW Don Sachs also has worked with Spatial audio and has their speakers

@russ69 Your suggestions?

Time to shop for new loudspeakers.

Kef likes Plinius sa100 and Mark Levinsons 331 , 332, 333.

@russ69 If I do it will be for a pair of Joseph Audio Pulsar2 Graphene, Fritz Cararra Be, Sonos faber Olympica Nova, or maybe Harbeth 30.2. As you can see I like stand-mount speakers. I think you would be surprised at what I am getting from these KEFs with the Rowland amps. The room is more energized than it ever was with the Spatials. But I know I can coax more from them.

@artemus_5 See my lengthy post from earlier this morning. Yeah, I know about Sachs and Spatial. They are excellent speakers, superb really, just can't live with the limitations. I tried.

@soix Thanks for the recommendations. I will look into them.

@jayctoy Do you have direct experience with these amps driving speakers in the Reference line? Tell me more, like sonic characteristics with these speakers.