Vogue Very Easy 8123 took me 2 weeks - a eternity by my own standards. I will admit that the instructions were clear, though I wish they'd just told me how to line the freakin' jacket (I can't easily extrapolate that with my current skill level) so that I wouldn't have had to come up with an alternative seam-treatment solution (aka seam binding). It's a pretty, vintage technique - which the pattern didn't instruct about - I just winged it by modeling the sewing experiences of others - but it's a time suck.
At any rate, I am happy with the results. I used a felted wool (I think) with a little bit of 4 way stretch - just a bit. Originally, I cut the pattern and did an FBA (full bust adjustment) but realized, after spending hours on the adjustment and the muslin, that it was grossly unneeded given the loose-fit and ease built into the pattern. The alteration itself was much more successful than my last attempt.
This time, I didn't do the Y variation - just the regular one - and then I managed to figure out how to remove the side dart by moving it to the front waist (which would have looked weird) and then shifting it to the side seam i.e. cutting it off. In the end, I managed to add room in the bust with NO discernible dart. That's a pretty spiffy alteration that I had to search high and low to find out about. I'm pretty proud of myself for having nabbed it, even if unnecessarily.
My second muslin (yes, I made 2?!), cut from the regular size 12 - but shortened through the waist to accommodate my proportions - showed the largely unaltered pattern sizing was fine and here are the finished results: