I prefer Holly because that's what I'm most familiar with. Mike makes a good point about the balance of economy and power with the Q-Jet's small primary and larger secondaries. I've never run an Edelbrock but they seem to be similar to the Q-jet. For me Holley's are a little easier to tune. With their needle jets Q-Jets remind me of a big snowmobile carb. Q-jets have a bit of an unfavorable reputation because tuning the needles is unfamiliar to some people. In my opinion this reputation is undeserved, as a properly tuned Q-jet is a fine carb. In the end it boils down to the proper size (the biggest is not always the best ) and what you're most comfortable working with. For me an electric choke and vacuum secondaries would be the options of choice on a marine carb.