The Tempest was my second boat. I went from a 10'6 inflatable AE AdvancedFrame to a 17' hard shell. Two completely different boats.
For people transitioning from a wide recreational kayak, the Tempest can feel tippy at first, but the feeling goes away after 20 minutes. Just try to put the boat on edge and realize that the secondary stability is awesome.
The Tempest is fast. I was able to cruise at 4.5-5 MPH accordingly to my GPS. Much more fun to paddle than the wide and slow AdvancedFrame. The seat is comfortable, but the back band can be challenging to adjust. I had an old 2009 model, I believe the new back band is better.
Tracking was good even without the skeg. Turning can be challenging without edging, but if you put the kayak on edge, it will turn 90 degrees with a couple of strokes. Long turns can be done easily just by rising one knee while paddling forward.
The main downside of the Tempest is the weight. My RM weighted 57 pounds and could be difficult to put on the roof rack when I was alone. However, very often a good Samaritan would offer help.
Fit wise, I'm a big guy. At 5'11, 235 lbs, and shoes 11, the cockpit was snug. I didn't feel cramped, but getting in and out required seating on the rear deck. Wet exits were no issue, but reentry could be challenging.
On a last note, the Tempest is a well proven kayak. If you are not completely sure about it, look for an used one, they pop up frequently on CL and they are quite easy to resell. It took me literally 10 minutes to resell mine.
The kayak tracks well. The storage capacity is limited. There is a bungee cord on the front, and some space behind the seat, but this space is hard to access if you are in the kayak. The kayak tracks well, not like a touring kayak, but better than an entry level hard shell.
The kayak is not very easy to get in, I am 5'11" 230lbs and I need to open the zipper on the front deck, thus it is almost impossible to take a splash on the middle of a lake as going back inside the kayak will be hard.
With regards to the weight capacity, I am a pretty heavy guy (230lbs) but I had no problems using the backbone. The kayak does not bend on the middle.
If water is cold, it's a good idea to inflate the kayak, let it rest on water for some minutes, and then top up the inflation. I have tried to over-inflate a little bit as well, it works, but it is not recommended by the manufacturer.
A couple of times people came to ask me about the kayak, because it doesn't look like and doesn't performance as the usual inflatable boat that people have in mind. I am very happy with this kayak, but For the price, it could come with an inflation pump.