The 282 is a great boat, traveling will be fine with 4, but I would only overnight with 2-3. The boat handles well for a 28ft boat.
The 305express has more space and creature comforts, and will easily sleep 4 and can cruise with up to 6 in comfort, it has more seating and a more cruiser friendly helm. I also am a big fan of the center helm chair, my 265 Express has it and the view from the helm is great, and makes site while maneuvering much easier.
Up sides to a 282:
It will cost less to buy, and operate
Can be kept indoors
Will not require bottom paint
Has a walkaround which is very safe for getting to the bow
Is easy to operate alone
Can be stored inside
Downsides:
Does not have a lot of helm seating for crusing in numbers
Will only handle like a 28ft boat in nasty seas, a bigger boat will handle better
Has a smaller cramped cabin due to the walkaround
Must cal ahead to have it put in, you cannot go out for a ride on a whim, boat may sit overnight if you come in and marina is closed
Upsides to a 305 Express:
Lots of helm seating for guests
More cabin space
Center helm chair
Has more interior cabin room and creature comforts, it will suit overnighting much better
Will ride better in rough seas
Has a larger hardtop and helm area to get out of the sun and in the shade
You can go out whenever you want since it is always in the water
Downsides:
Will cost more to buy and operate
Cannot be stored inside
Requires bottom paint, will need a barrier coat and then ablative paint, barrier coat isn't cheap and a gal of ablative is about $240/gal, you will probably spend about $1300 on paint if you do it yourself
Will likely need 2 to operate in most conditions unless you get the thruster to help you dock in wind
You really need to sit down and think about what you are going to use the boat for. Since you will not fish much, both boats will suit your fishing needs without a problem for the few times it is used to fish. As for cruising, the 305 is better suited, but you need to determine if the added expenses and keeping it in the water is worth the added cost. Decide how many will normally cruise with you, is it you and your wife mostly, do you have young or older kids? Decide on a normal trip how many ables hands you will have to help handle the boat. The 282 can be done alone, but I would recommend 2. The 305 really needs 2, with a bow thruster in most conditions you will be able to do it alone, but having you and someone to help is recommended, plus the thruster costs more. If you only have 2-4 on board normally, where will they likely sit, do you think they will want to be around the helm in comfort, or spread out in the boat, maybe the cockpit also? Will they want to be in the sun, or maybe in the shade? The 305 will provide more shade and helm seating, if that isn't important, a 282 will work well. Decide how far you normally will operate the boat, you can check the range and fuel numbers both on the Yamaha website, and the Grady website. If you only cruise local, either will work well, if you will be going outside the inter coastal and running more distance, a bigger boat is nice for seas you may encounter, but it will cost more in fuel. If you plan to run to the Bahama's, the 305 may be the way to go because that ride can get nasty quick and you may need the extra weight and comfort to do it right. Also think about if you will ever overnight, if you will more room is worth consideration. In all honesty, I do not use my cabin much, over the summer I will sleep on it once in a while before going fishing, but once on the water we only use it for the head, so more space would not benefit me, think about how you will sue it and if you need more space or not. More is nice, but is it necessary.
I'd suggest doing some research on both, make a list of what you like and do not like about each, walk on both models and make the list, if possible do it on the same day or better yet one after the other. Try and estimate the cost of each, that list and price will put things in a better perspective for you. When you look at each, maybe bring some friends to simulate how it will feel with the amount of people you plan to bring on a normal trip, see if it is cramped or feels right. If you are still unsure, then sea trial each, and see what you feel you can handle, some think a bigger boat is too much, others love it, one may ride way better then the other, or one may be just good enough for you. Hope this fuels your mind and gives you some things to help make your decision the right one.