Well, I've finished the project but I'm having some trouble with the sizing. I have a 46" bust and I like things a bit generous, so I worked mine to be somewhere between an XL (to fit 46" bust) and a 2X (to fit 50" bust). Note that I got gauge according to the pattern and that I blocked successfully to the dimensions outlined on the schematic included with the pattern.
Problem 1.
It doesn't come anywhere near meeting across my bust. So we tried it on my mum who's littler than me (44" bust). No chance of meeting on her either.
Problem 2.
The allowance made for the arm hole is not sufficient for a "generously" proportioned upper arm. I had a suspicion that this might happen when I was knitting it but I ignored my concerns and trusted the pattern. Even Mum's arms, which aren't as flabby as mine, are still an overly snug fit.
Problem 3.
Just too damn tight across the back on me and not much better on Mum.
The pattern at one point notes that the length of the back piece should be equal to one quarter of the desired chest circumference. This doesn't work for me. I think that if I try to make this again, then I would need to a) cast on a slightly wider back piece and b) make the wider section much wider to make larger armholes which would also increase the coverage across the bust.
All is not lost though. One of my best friends is much littler than Mum or I and this colour would really suit her, so hopefully the Ester will fit her.