Julie, is this your broker (i.e., buyer's rep) or the seller's?
I don't think it's unreasonable to ask the broker to start the engine while you're there to see the boat. Asking to go for a ride may be a bit more of a stretch. As has been said, you get that chance during the survey and sea trial.
Have you checked with the folks at Choosing an Ericson 38?
They may be able to point you to some E38 owners in your area.
The broker started out as "ours" but then the owner contracted with him to sell the boat. So now I'd say the broker is really with the seller.
After we saw the E34 at the broker's yard, we researched the E38 probably more than most would. I've been over at the Ericson forum and asked a lot of questions, including who's in my area. We've read countless comments from owners and reviewers alike. If there's an article on the E38 we missed I'd be surprised.
Maybe some don't understand this but I get a lot out of feel. I can't explain it but when I'm on a boat or in a car or "one with" mechanical things, my feel senses give me a lot of feedback. Right or wrong, I've gone with that all my life and it's worked, for me.
The problem with getting all your information from others is trying to filter it to fit you. Like beauty is in the eye of the beholder, what may be perfect for one person may not be for you. The E38 has had a lot of great reviews from owners but didn't they buy the boat because they liked it? The pics I've seen don't give me the warm fuzzies but I'm not letting that override everything else I've learned about the boat.
Anyway, we'll see it next week and I'll know a lot more. And I'm not pushing for the sea trial.