Here's a link to better numbers on the Ericson. ERICSON 38 Sailboat details on sailboatdata.com
And here is another link that might help. Sail Calculator Pro v3.53 - 2000+ boats
And this link is for Yachtsnet UK, a brokerage that keeps all their pics and info in their archives here. Archive boat data from Yachtsnet Ltd. online UK yacht brokers - yacht brokerage and boat sales
I think the foam between the inner and outer hull of the Etap will absorb moisture and therefore weight over the years.
Contest is a solid well built boat - as posted some sail better than others.
Sadlers, designed by David Sadler (designer of Contessa 32) and Martin Sadler are well respected in the UK and good sailers all.
I don't think it makes much difference to resale - a well informed buyer will research the boat if less well known. And at the risk of ruffling feathers I think a lot of European boats are better built and designed than many North American built boats.