Update - I went with the Mackie MR824s and the focusrite 2i2. I was set to go with the SMSL but got a focusrite used on the cheap.
I did a quick in store listen to make a short list and brought 3 pairs of monitors home to live with for a week - the MR824, JBL308, and JBL306.
I also listened to the Adam T8V (too bright), KRK Rokkit 8 (great bass, but didn't like vocals through them), and Yamaha HS8 (also too bright for me). The Kali LP-8 had an audible hiss from a couple of feet away, so I passed on them. They didn't have the more expensive Mackie HR series.
Setup was a snap with the focusrites just using the line-in and line-out. Never messed with anything on the 2i2 except the monitor volume.
Short story - we kept the MR824s.
Overall the JBL 306p had, in my opinion, the best sound. Bass is very respectable and it had the most natural sounding vocals to my ear. There is some hiss but outside of a nearfield situation it was unnoticeable in my home office.
The Mackie MR824 was almost as good sounding as the 306p, with substantially deeper bass extension. I think it's ugly as heck but my kid doesn't care.
The 308p didn't seem to be a smooth in the bass as the Mackie, and seemed to be audibly quieter from the upper midrange through the treble. Honestly, I don't think the 308p and 306p sound all that much alike. The Mackie and 306p sounded more similar.