I'm with Ingrid - GORGEOUS sweater. This goes in my to-do pile
You asked if it was a 'reasonably un-complicated' pattern. Not knowing your level of experience, as long as you're not intimidated by cables, and you're comfortable with the "make 1" increase - the only potential complications I can forsee is in the finishing steps.
Quick read-thru, this pattern appears pretty straightforward EXCEPT for the 2nd and 3rd items in the "Finishing" section.
If you've done socks, Kitchner won't throw you. If not, do not panic, it only seems intimidating at first. I'm positive Amy has good videos up.
The "sew cable extensions to back neck edge" are probably your held stitches from the back of the sweater ... unlike others, I often have trouble visualizing the abstract, and will need to physically see the sweater to get that instruction around my brain.
I'd say go for it -- and thanks very much for posting the link. Definitely a keeper.