Can you tell me why I didn't like the Reference 3a MM's?

OK, who am I to give advice when I picked out my preamp and amp before choosing my loudspeakers?
Here is the conundrum. Many of us (myself included) believe that source and electronics and cabling are more important than choice of loudspeakers. This drives the other camp bat-shite crazy. That's fine, we are all entitled to our own opinions. 
My experience from 45 years in the hobby is that with everything else carefully selected, a very humble set of loudspeakers can sound amazing. On the other hand, the finest set of loudspeakers imaginable will always sound like crap fed a crappy signal. 
Sounds like I am arguing for your course of action and not against, doesn't it. Yep. I am. But now you have to choose your loudspeakers carefully. Anyone and their brother on this crazy Board can throw out suggestions for relatively efficient loudspeakers but they are all going to sound different in your room and may or may not suit your preference. Asking here for suggestions is worth maybe 5 cents and a used piece of gum. 
I happen to have spent ten great years loving a pair of B&W Matrix 805's I bought new in 1998. Your 705 S2's are basically the same loudspeaker with technological advancements. That means they image like champs and have a very pure sweet midrange but don't give you the immense wall of sound that only larger speakers can provide. For example, I remember taking the Mapleshade recording of The ARC Choir to my retailer and with the larger B&W floorstander's I heard the complete choir spookily in front of me while I could not coax the same with the 805's. 
But....you have not given us a budget and you have not told us what you like in the way of speaker attributes. Every loudspeaker on Earth has strengths and weakness and character traits. No exceptions. 
My first piece of constructive advice is decide your budget and which speaker characteristics you like. Then call Galen Carol and ask him. 

Erik, it would have been easy, perhaps, for you to interpret my comments to mean that in my opinion source and electronics have a greater influence on sound character than loudspeakers, but I never said that. I only said they are ultimately more important to SQ. Put differently, I happen to agree that choice of loudspeaker has the largest effect on the character of the sound, just not the quality of the sound. 
Angelica Huston's nose might be the largest contributor to her facial character but it sure as hell does not have the largest effect on her perception as a talented actor. So to use that most unexpected analogy-I am sure-I would rather have an Angelica Huston with her mind and personality and a different nose in my cast of actors were I to be a movie director than Angelica Huston's nose on someone else who lacked her talent. Perhaps this registers with you. Perhaps not. I don't care a wit. 

As already noted, an efficient lively standmount is something of a contradiction in terms. There are ways to get around your gain problem too. 
This comment has me scratching my head;

I really need to stick with Bookshelf, as my "listening room" is my garage and the speakers are about a foot off the ceiling and wall for protection.

Protection from what? I hope you don't mean your cars! Placing your speakers only a foot from the ceiling and from the rear wall is inherently problematic. Why? Well for starters that creates a room node problem. Second, most bookshelf speakers are ported and despite their name, never sound best on a book shelf. They need to be away from floors, ceilings, and walls. I am curious as to how you have them mounted there. 

I saw you only had 13 posts and I was impressed by your humble photo/avatar and figured I would try to help you out. You have a lot of very nice gear for that environment. 
With that, I'm out :-)