I had a 2006 284 w/ twin 250 Verados. I liked the boat. It was a very good value for the price. It is a BIG 28 footer. wide (9'10" beam), high gunwales (mid thigh+ and I am 6'1"), plenty of room, plenty of storage. Boat was solid as a tank and would really be able to hold its own in rough water.
Fit and Finish - Mediocre. Certainly not the best, but also not the worst - again VALUE, you are not paying the same as boats with the fine fit and finish
Wiring - I give it a C+. The factory wiring was passable (but you will want to "clean it up some"), the stuff that was done at the dealer (in my case Bass Pro Shops - Dania) was horrible.
We bought new. Had a nice sized list of "small things" when we brought the boat back the 1x that we did for service and warranty correction. That ordeal was enough that we never went back for service - and let a few additional warranty items slide - just was not worth it to go through the hassle of bringing it back. Some of the small issues. busted gas shock on one of the hatches (several of them broke after that - not high quality stuff) some of the hatches leaked - the bench seating up front is supposed to be water tight -it is NOT - never will be, the door to the console/head compartment is a poor design. also has a hard time staying water tight. their "fix" was to add a latch on top (rubber - tensioned) I spoke at length wiithe the factory about this and was fairly surprised to see the same latch on new boats at the boat shows 2 years later. they should have fixed the issue. we had a short in the molded in spreader lights, fuel tank sender was bad, afew screws that backed out - shoul have been bolts, etc. all small stuff.
Boat ran very well. good in a head sea, but not great (21 degree dead rise) took some finesse to get good at running into a head sea. However the boat more than made up for it in stability. The boast was one of the best drifting, trolling boats that I have ever been on. It was also very dry. It was not the most economical boat around. the beam and bulk had a price. also not the quickest - but plenty fast for me. With the generation I Verado 250s I averaged 1.2-1.6 mpg at most cruise RPMs at a speed of 22-34 knots. faster than that and it dropped off considerably. That is with the thirsty Verado Gen Is, but I had friends with the same motors on more efficient hulls and did better, so I knew it was the boat. Everything has a trade off. A good, solid, safe, all around boat. Watch George Poveromo's show - same boat - you can see the room it gives you and get a feel for the performance.
Would I do it again - yes. But in todays market (a little different than 11/05 when we started looking and 01/06 when we took delivery) I would be looking hard at a late model used boat. For the same dollars as a new 284 you could probably get a 2-3 year old Sea Vee 29, Pursuit, or somehting like that - a tru step up over the mako. That would probably be the route that I would go today.
I will say that - even new - I would have the boat surveyed. Not just a Mako, but any boat. Good Luck!