Welcome to the forum Robert.
I haven't sailed on a W28—only my W32—and I'm no expert. I did seriously consider a W28 and I think they're beautiful boats.
You might already know this, but all displacement hulls have speed limitations based on the length of the boat. A longer boat's top speed will generally be faster. The W28's top speed through the water is 6.5 knots, vs 7 knots for the W32. So the W32 can technically sail faster.
W28s are lighter so they need less wind to get them going, and the sails and tiller will be physically less demanding. The downside of being lighter is that the W28s will also be a bit more bouncy at anchor and at sea.
W28s also have a more cut away forefoot (the front part of keel) which allows them to turn more sharply. Conversely, the W32 would track straighter and heave-to nicer.
W28s have a less full hourglass shape meaning they would tend to stand upright allowing the keel to dig into the water. An upright boat sails upwind better. The W32 with its more full hourglass shape rolls on it's side a bit easier but is harder to knock down (more secondary stability). If a W32's skipper trims the sails and keeps the boat upright, I think it will sail upwind just as well. I think the W32's "wet" label also has to do with skippers sailing with too much heel.
W28s are less boat to maintain and less dock space to pay for. On the other hand, there are fewer of them for sale and asking prices from what I've seen tend to be pretty close to the W32.
You could say the W28 might be less boat for the buck, but great savings longer term for a more maneuverable boat that's easier to sail.
Or for a similar dollar amount, you might opt for a steadier, roomier W32.
My W32 has sort of become an obsession.