We just sold our 00 396 last month. Just a matter of not using it as much due to my sons baseball schedule etc. The last two seasons saw about 20 hrs of use, so it just didn't make sense to keep her any longer.
Ours was a gas boat with twin merc 7.4L 385hp. Fuel burn was around 36-38 GPH at cruise which was around 32-3400 rpm, that would give a speed of around 15knts depending on current and wind direction. Good displacement speeds at about 10kts would still burn around 25gph, not really a fuel efficient boat no matter how fast or slow you go.
The 396 handled really well in close quarters on calm days, you just had to be aware of the wind at all times, any more than just a little cross breeze and you could have your hands full. Out in the upper to middle Chesapeake where we cruised she gave a dry and solid ride no matter the conditions.
The aft deck was a little small compared to other boats her size but that space was made up in the saloon area, nice and roomy.
As mentioned before, the cost of a diesel is more than a gas boat, so, if your gas usage is low you probable won't make up the difference.
We loved the boat and never had any major problems but it just didn't make sense to keep her at the rate we were using her.
Good luck