Quote Originally Posted by derekcohen
Ian, I'm sorry to say this but the #90 is a poor substitute for a shoulder plane (your great grandfather and father must have had/have amazing hand control!). Compare it to a #92 or #93 - it lacks the "nose" section that is necessary for registration.
Derek, I think it comes down to technique. As you rightly say, a shoulder plane has a long nose which is used to register the plane. The #90 doesn't so when trimming shoulders you can't take a continuous swipe with it. Dad rarely uses anything other than power tools these days — he was well into his 70s before decent power tools became really affordable and now, at nearly 84, he finds pushing a plane just too much like unnecessary work — but back when he was younger I seem to remember he used to trim shoulders by working both ways from the centre. M&T joints done back then are still square.

ian