I have Lake 238s, very similar to what you're considering. They're nice shoes, but their sizing guidance seems to run big, and their sizes also seem to run big: according to their guidance, I should be a size 43, even though I'm usually a 42. I ordered the 43s and immediately exchanged them for 42s. Even those seem a bit large and I'm wondering if 41 or 41.5 might be better for me. Although they do have lugged soles, they're not very walking-friendly. They have a full-length carbon-fiber sole plate. I've got a pair of Pearl Izumi shoes that are quite a bit more walkable, but the flexibility makes them prone to give me hotfoot after about 40 miles.
I'm also using SPDs. For a very long time, I used Bebops, and wish I could still get them. One of the things I especially liked about them was the float: SPDs have 5° (?) and Bebops had 15°. The nearest equivalent is Speedplays (which use 4 bolts), and I'm thinking about sucking it up and trying them.