I highly recommend a stack of 12-3 straight and 12-3 slant.
Love my 12-3 trio. I have str - slt - str.
If I were to change it - I’d likely go slt-str-slt.
A couple guys on here are really liking the 15-12 stack but like you it would drive me nuts. I’d either have to go all 15’s or 15 and 210….
I have just the 15-3, and it is glorious! @Joeykun can chime in on characteristics of the 15-3, 210-3 stack. That will be my next move when I want to add to my 15-3, which fills so many of my needs at this time.
Thanks a lot for your feedback everyone! But, as I already feared, it seems like a standoff between a second 12-3 and a 15-3.
I got to spend some more time on thinking about my needs and, taking my circumstances into account, I believe a slanted 12-3 would be the more rational buy. I could pair it up with my existing 12-3 without going nuts over the mismatch.
With the 15-3 I would be "forced" to get another 15-3 or 210 down the road, which would mean another couple bucks invested into gear. But it is still extremely tempting to get one of these. GAS is real.

