Couple major items to be aware of -
1st - check with your airline and their policies, even with the latest legislature (for us here in the US) it allows, in reality, each airline to set pretty much it's own guidelines. The recent Maui trip was on AA, on a Boeing 767 roundtrip, I took my Taylor miniGS and it fit perfectly in the Overhead, either of my dreadnaughts or others would not have.
2nd - go even further, check to see what type of plane you will be on, each distinct airline designs each distinct plane to their needs and specs. So, a 737 on AA may and well might be (interior wise) a bit different than say on Delta. There should be a description of the aircraft's overhead bin size, even as far as the size of the bins in the different classes (IOW - 1st class may be bigger than say, coach...)
3rd - last year, the legislature was not in place, even as it is (supposedly) I have found most of the attendants up on the counter are unaware of the article, take a copy along with you and even write down or make a diagram/ layout of your case along with measurements, that and the weight is how these items are viewed. Be aware that according to the legislature, Guitars and such should not be subjected to any additional charges as for oversized/overweight, yet most if not all Airlines are counting them as your first (and most likely only) carry-on or as your first checked bag.
4th - in almost all examples, the TSA will open and inspect the contents of your case, even my soft case Taylor mini was opened after going through the x-ray thing.
In example - last year, i had a ticket on AA which allowed me one checked bag, one carry on and a personal item. I also had an additional fee which allowed e to board early, this ensures (usually) you will have OH bin space. I went to the curbside check-in, gave the guy a $10 and he walked the guitar case down. I checked in using the internet, having my boarding pass I proceeded to the 'please remove your shoes sir' line and waded my way through. So, I got on the plane with a smallish duffle bag and a stuffed back pack. You need to check with, once again, your airline and make sure your carry-on and personal item fits their guidelines.
The one thing I did do was spend $300 plus tax on a case, and as I watched the bag handling guy in SJC look the case over, then drop it, face down onto the conveyor from a steeper than 45 degree angle I knew that if I had to check an expensive guitar that $300 looked pretty cheap. Honestly, I have traveled extensively back and forth to Vegas and Southern Cali with an older, cheaper guitar in a $100 or so "Gator" type hard shell case, never had a problem. NO airline will cover damages in any way if your piece is in a 'soft/gig bag' type case.
I do know Dave Nachmanoff was bragging about the case he now uses, add in the fact the guy is always on a plane.......
Dave??? You out there??/
Link to the SKB iSeries I own - I always get questions like 'how many guns ya got in there'? "where ya going hunting at" etc....
http://www.skbcases.com/music/products/ ... &c=75&s=75