We ALWAYS drive to HH & almost always fly to WDW. Several reasons: I think you really need a car to enjoy HH & we tend to want to bring more STUFF (i.e. boogie bds., fishing pole etc.) that makes packing a car easier than luggage for the plane; we always go to HH in the summer, so we have a little more freedom/time for the trip & therefore, driving doesn't make us feel like we are losing valuable/limited vacation time; we make the drive to HH like a mini pre-vacation, making at least one major stop - usually taking in some history. One of our favorite stops was Richmond, but there are several great Civil War stops along the way. Finally, since we usually go to HH at the end of Aug., the weather is so "iffy" many times under the threat of severe storms (one year they actually discussed evacuation plans w/ us, but the storm missed us.) that we are not as comfortable with flight plans.
Bottom line, HH is worth the effort. We never thought we would like it as much as WDW/OKW, but we have come to love it's different charms, as long as the weather is good. Best of luck in whatever plan you set. SGG