West Bay is on the same side as the West End. (northwest)
The contrast you're looking for is probably the West Bay/End vs. the South Side.
The reef structure is very different north vs. south.
In general terms the difference is the north is slightly rougher, often more larger stuff like turtles, cuda, grouper, etc. Diving is occassionally shut down by storms in the winter on the north side, almost never on the south. The bigger shops with the resources will move their boats south, the panga operators just wait it out.
The south has been described as shallow macro diving in some areas. The south east also sees wild dolphins and infrequently whales. The only sharks seen off Roatan are at the shark dive on the south side and Anthony's Key on the north has the dolphins. The "signature" dive on Roatan is arguably Mary's Place on the south side. Whale sharks are an infrequent occurrence, more prevalent off Utila.
All this is a generalization - review my previous posts, posts by Doc and other Roatan regulars for more detail.
The East End is harder to get to so more pristine also. Not as settled, not as dove, Generally supposed to be good diving in that area. Most day boats from the resorts do not go out there regularly. Some run special trips, usually charging extra. A couple of the NE side resorts do go there infrequently.
Also, how far are the beaches from the west end?
Half Moon Bay Beach
is the West End. But it's not a very nice beach, narrow with a road running just behind it. Both ends of the bay are low ironshore cliffs. Most of the dive shops/stores/resorts are on the other side of the road from the beach. Even the properties that list beach access - such as Posada Arco Iris - require you to walk across the road to their beach area. It's a thin beach with several docks bisecting it.
The beach in West Bay is the nicest on Roatan - the one that gets written up in all the tripadvisor reviews - because that's where the cruise excursions go. It's 2 miles from the center of the West End to the center of West Bay. The road between them isn't especially safe for walking at night but there's cabs available most of the night in the West End. There's also a water taxi that runs between the docks on both beaches till about 9PM or later. Sand flies are a problem on both beaches.