I've tried only a few jackets from Boden, but I would agree with the input above -- for me, size up unless reviews suggest the item runs large. (I'm usually a 6P or MP in J. Crew and Ann Taylor, "full hourglass" shading into IT range; took 6P in the Fifties Jacket, felt 6P in the City Wool Jacket was too small, will soon be comparing 6P and 8P in the British Tweed Blazer). Shipping was kind of on the slow side, as were returns, but at least I had a promotion that included free return postage. Ironically, the item that was shipping from the UK arrived before the ones being shipped from the U.S.
BTW I've found out about some promos I wouldn't have known about through this blog (http://mysuperfluities.blogspot.com/), such as a code for 20% off their spring 2014 preview. It seems to me that some popular items run out before they ever get close to sale, so I ended up ordering something from the preview, which is something I ordinarily never do for retailers like J. Crew. Shipping in nine weeks...talk about delayed gratification! (FWIW, I read somewhere else that preview items ship from the UK and therefore may arrive later than items ordered from the regular launch in the U.S.)
ETA: I was curious about my recollection that some things took their time getting to me. For an order placed late on a Tuesday night, one item left the UK on Thursday, and the other two left the U.S. warehouse on Sunday. Another order, placed over breakfast on a Monday morning, was scanned in by UPS the next evening.