Willard made the Willard 36 from 1961 thru 1970. Somewhere around 1972, they launched the W40. We've owned our W35 for 25 years and have ocassionally considered upgrading to a W40, mostly for the second stateroom. The W40 also has an exceptional engine room for its class (still a crouch affair though). If we were to start from scratch, we'd go with the W40. But benefits are not so grand that it offsets the expense and difficulty in swapping boats. Plus after 25-years, there's sort of a bond with the boat.
I have spent some time on GB36s. Personally, I consider it the absolute gold standard in trawlers for entry level people (even though GB calls them "cruisers" vs trawlers). They handle exceptionally well, are well suited to a single engine, and there's plenty of space for the average family with some friends. Plus they are large enough to cover some ground and cruise if so desired. Despite the legions of similar designs such as the Monk 36, the GB36 stands out with a certain fineness of design. I suspect that had I fallen in love with a GB36, I'd be equally hesitant to upgrade to a GB42 as I am with my Willard. Maybe even more hesitant since I really like single engines and so few GB42s were delivered with a single.
1970 Willard 36 Sedan Trawler