Ok everybody. Pull up a chair, Ken is pulling his soapbox out again!!!!

Here's my take on it. And please remember that this is my take on it, only my opinion. The "extras" on the Nexstar are what I consider "gadgets". Great Planes has put them on there for one thing and one thing only, to sell airplanes. Think about it for a second. If you are standing in a store and you're looking at 3 or 4 boxes with planes in them and you're trying to decide which one to buy, what are you going to be more likely to walk out of the store with? The Nexstar because it's got all of these things that "make it easier" to learn to fly. As somebody that doesn't know how to fly you don't know any better, and you want it to be as easy as it can be right? They are a sales gimmick. Now don't get me wrong, they do in fact have an affect on the way the plane does fly. They do make it "easier" to fly, in fact they make it too easy to fly. Look at the AFS first. This is a co-pilot that assists you by leveling the plane for you. This is the worst of the 3 gadgets (AFS, speed brakes, and wing droops) because with this you never learn to recover and level the plane yourself. This one is really bad IMHO because you become reliant on the AFS and never learn the skills you need to move on to other planes. The other 2 gadgets are ok to leave on, but I prefer not to if I have a choice. The speed brakes do slow the plane down. Why do you need to slow down a trainer? A trainer is designed to fly slow anyway and I don't see why you need to slow down anymore. Same thing goes for the wing droops. They are there to prevent "tip stalls", as well as other things. Tip stalls are rare on a trainer anyway (see the flying slow I mentioned above). Both of these can be taken off and the student learns to fly "just the plane" and not the gadgets. Think about it for a second, pilots have been learning on "plain ole" trainers for decades. Heck, the older trainers didn't even have ailerons. If you were to ask my opinion on the best trainer out there judged by flying characteristics I would probably tell you the Sig LT-40 (although there are others that are very very close to the Sig). It doesn't have all the gadgets on it and the student learns to just fly the plane. As I said above, if you learn to rely on the gadgets your pilot skills are less than if you learn without them.
As a side note (and I'm sure I'll stir up some controversy here) I say the same thing about the Hanger 9 P-51 PTS. Yes, it is more mild than a full bore P-51 warbird, but it isn't as mild as some of the trainers that have been around for awhile. The P-51 PTS is a sales gimmick, nothing more (once again, this is only my opinion). Hanger 9 has figured out how to capitalize on new pilots wishes. I can't even begin to count how many times I've seen new pilots show up at the field with a P-51 warbird to learn on. Heck, it's a great looking airplane. I love the looks of it too. All Hanger 9 did was to find a way to sell a "trainer" to those people drooling over that warbird. But it's not a trainer for everybody. It does fly fast, and it does have a few bad characteristics. I think that those pilots that are "a natural" will do fine on the PTS, but once again it's not for everybody. There are those that are going to need to stay on a more traditional trainer (and I feel that this is the majority of new pilots out there) to learn to fly, and then maybe move up to the PTS as their second plane.
So to sum up what I think of the subject, both the Nexstar's gadgets and the P-51 PTS's gadgets are sales gimmicks. They are there to sell planes, period. Yes they do change the flight characteristics of those planes, some will say they change for the better and others will say they change for the worse. But these are only 2 of the many trainers out there, and all of the other trainers out there don't have these gimmicks and there are plenty of people that learn to fly just fine on them. In closing let me throw this last thought out there. Think of the gadgets on the Nexstar as a "cheat sheet" you make up for a test. If you go in and take the test with the cheat sheet you will pass the test, but you won't know the subject. But if you actually do the homework during the semester and study for the test then you are more likely to come away from that test with a solid understanding of the subject. Same goes for the "gadgets" on the Nexstar. With them you can fly, but your skills aren't going to be as good as they can be. Without them your pilot skills will be solid and you can rest assured that you are ready for more advanced planes.
Ok, that's my 2ยข worth
Ken