The AL-3, all of the ALs, also have 3db more attenuation on the squawker than the AA/A crossovers.
This changes the balance a bit. You might argue a lot. The woofer and tweeter will shine a little more at a given volume, not a bad thing in my books...
I have been fortunate enough to have owned a few LS, the first pair having the AL-3 crossover. Here’s the thing... I knew I was going to eventually own a pair and had actually bought a pair of A/4500s and CT125 tweeters PRIOR to even finding my first pair. The AL-3 pair of LS I lucked into first sounded so good to me I never even tried the A/4500s out in the year or so I owned them. Yup, they sounded that good.
The second pair I owned had the plain old AL crossovers, and despite all the negative reviews, I didn’t think they were in need of any immediate assistance. But I tried the A/4500s and CT125s in them and was impressed in a different way. The were so “refined”. Almost out of character, but ever so well behaved, and at high volume too, which I found surprising for a first order crossover.
The pair I have kept are LSI Splits and have the K-43 woofer which rocks with anything that’s put on top of it. I have tried the AL, A/4500, and AA crossovers in them, ALWAYS with the CT125s or CT120s, and could be happy with any of them here.
Now here’s the kicker... I bought a pair of AB-2s recently (AL-3 minus the tweeter protection) but moved just days after receiving them in the mail and haven’t taken possession of the new pad yet.
I have all of the requisite parts for a head to head shootout (AA, A/4500/AL-3) but I don’t have the venue, yet.
From my experience so far though, I think any “experimental” money would be extremely well spent first on DE-120s on whatever lens you can find that will fit into the LS. Preferably the elliptrac or SMAHL. And I thought the K-77 sounded fine until I heard CT-120s in the same application.