Matt,
Here are my thoughts...
Wood boats are a lot of work to build and maintain and they need to be babied to some extent... Size for size any one of the devlin designs will kick the ass of a tin boat in terms of seakeeping ability and will triple kick ass in terms of looks and function.
When I say they need to be babied, I usually get 27 responses from people saying I'm full of shit and they run their boat hard and blah, blah blah... I've owned a snowgoose for 5 years and semi-babied it and it got pretty beat up over that time and I fixed little things as they came up along the way, I'm also on the water 50-75 days a year with it. They are plywood covered in epoxy and glass, if the epoxy is breached, the boat is compromised, so great care is needed in terms of installing and properly bedding hardware and fixing points of wear or damage. My perspective is that these boats are not boats that you can beach on a rocky shore and let sit there and grind on the rocks, you can't pull your anchor chain across the sheer or slam an anchor on the deck, etc... these things will leave marks and will cut through the epoxy, allowing water into the wood. The fixing and maintaing is easy, since you built the boat, it takes time though.
As far as seaworthyness, the Devlin designs are much better than a tin boat and get better as conditions deteriorate (so you can use a smaller boat that is easier to hide which increases functionality). They tend to ride with a bow up attitude at low speeds and are decked, so you take on dramatically less water than an open boat. This is a subjective evaluation and open ot lots of arguing, but in terms of seaworythness, the devlin designs add 2-3-4 feet compared to a tin boat. That is a 16' Devlin boat in bad weather would be similarily safe to a 18' tin boat or more. I know if the weather got really really bad, there are few tin boats less than 20' I'd pick over my 16' snowgoose and the ones I'd pick would be self bailers.
Other downsides are the Devlin boats take a lot of HP to plane because of their hull design, so they are more expensive to power.
One caution is they are a huge investment in time and money and should be thought of as a specialist's custom boat, in my opinion. The boat is a 2-300 hour investment to build and an annual investment as well. I see far too many folks build them only to build them bare bones without the niceties that all the effort put in deserves. I'd say before you build one it is important to know what you want the boat to do and to spend the extra time to build the boat with the attributes that will increase it functionality - like well thought out wiring that is concealed, shelves and cabinets that serves as spots for storage, good drainage, easy access to all parts of the boat, cockpit covers to keep your gear safe, integrated blind, etc...
In my opinion though, they are worth every bit of effort!
Tod