I have been on "the list" for this tool for nearly 6 months, but today it finally arrived. Not cheap at $299 shipped, but it is a thing of beauty! Light in weight, very nice walnut handles, a pleasing and I believe very functional blade profile, and it just plain feels good in the hand!
I previously had the Two Cherries inshave and it worked well. The profile of that inshave is similar to the Avery profile, though the edges of the Two Cherries blade are a tighter radius and it is a heavier tool. A radius profile on the edge of the blade is helpful in getting a clean cut along the gutter edge, and that area has a somewhat sharper curve than other areas on the seat. When I was notified of the shipping on the Avery I sold the Two Cherries inshave.
I also have the Barr scorp and use it a lot on my chairs. The Barr is very functional and does a great job, but the scorp "radius" profile does leave a lot of tool marks. I remove most of those with my travisher, but on the flatter portions of a Windsor seat (leg areas and the very center of the butt area) I think this inshave will shine. With 8 Windsor dining chairs on my current "to do" list for my lovely wife, it is sure to get a lot of mileage in the next few months!