Your profile says not certified, and if you are completing your OW dives, or doing your first dives out of class on your trip, Mike Severns is not the dive op for you.
As already stated, a lot of things depend on where you are staying, and what transportation you have. If you are staying in the Kihei/Wailea area, and are a new diver, I highly recommend the B&B Scuba operation. They have been around a very long time, and they are extremely good with new divers. In fact, I did my first Hawaii dives off their boat! They go out very early, so you are back early and avoid the winds, and have the afternoon to do other island things.
But if you are staying up in the area from Kaanapali to Lahaina, or north, they would be quite inconvenient. I honestly don't know the dive ops up there well. I have done one day of diving with Lahaina Divers. We did a dusk dive on the Carthaginian and a night dive on the Mala Pier, and I was quite satisfied with their operation.
There is a lot of good shore diving on Maui, much of it quite easy. You can hire a DM from a local shop to help you out, or, if you have a bit more experience than your profile suggests, you can try it on your own. If the surf is quiet, it's not at all difficult to do Ulua Beach or Old Airport. Check out shorediving.com, or alohashoredivers.com, for information on Maui shore dives.