Awlgrip and Awlcraft 2000 are manufactured by US Paints. Alexseal is a newer product manufactured by Mankiewicz Coatings.
Awlgrip is a different product than Awlcraft 2000. Awlgrip is a polyurithane manufactured by US Paints. When it cures a fine clear coat rises to the surface. This clear layer is what makes the end result "shiny". Because the clear layer is so thin, it isn't recommended to compound or "buff" Awlgrip. Yes, it can be done, but there is very little product to remove to restore shine. Most of the time you will end up with a nice shiny hull that flattens to a dull finish as soon as the check to your detailer clears. Some painters will finish a topcoat with a coat or two of "clear". In theory this ends in a more durable finish with a thicker gloss, but it is not necessary and not typical. Awlgrip can be applied by brush (roll and tip) or spray. Awlgrip was originally formulated a long time ago, but due to EPA restrictions has had to reformulate numerous times. Current Awlgrip product is not as wonderful as it once was. Additionally, Awlgrip is nearly impossible to repair. This is because the repaired area can't be wet sanded and polished to blend the new material into the old. Typically, an entire large area (think the side of your hull, or house side) is painted just to repair one small scratch. Alternatively, a square around the scratch is masked off, sanded, faired, primed, and painted. This leaves a square paint patch that is obvious when you are up close.
Awlcraft 2000 is a newer product also manufactured by US Paints. Unlike the original Awlgrip, Awlcraft 2000 is an Acrylic Urithane. Awlcraft 2000 is much softer and less durable than the original Awlgrip, but is much more forgiving to apply. Awlcraft 2000 can only be applied by spray. Brushing (roll and tip) is not recommended as it is nearly impossible to get consistent results. Unlike Awlgrip, Awlcraft 2000 can be buffed to restore the glossy finish. This is because there is acrylic "shine" all the way through the paint thickness. Old oxidation is removed and new "shiny stuff" is revealed in the process. Awlcraft 2000 is the easiest of the three mentioned paints to repair. Instead of having to mask off an entire large panel section to paint, you can simply repair the immediate chipped/scratched material and wet sand/polish to blend in the repaired material.
Alexseal was invented/formulated by the same guy that created the original Awlgrip back in the 60s' or 70s'. In my opinion, it is the best of both worlds. It is a standard two part polyurethane so it is as tough and durable as the original Awlgrip. It can be sprayed or brushed (roll and tip). It has shine all the way through so it can be polished to restore the finish. Because it can be polished, it can be easily spot repaired as well instead of painting an entire masked off section.
With that said, those are three very good paints. I started off with Awlgrip and made the move to Alexseal because of it's capabilities. I painted my 70 footer stem to stern in Alexseal and I'm very happy with the results. With that said, I *highly* recommend sticking to whatever your painter is familiar with. It doesn't make sense to pay for the guy's education in a new product. Additionally, the top-coat is the easy and satisfying part. 99% of the work is the preparation of the sub-strait. The top coat will only augment how good or bad of a prep job was done.
Here are some photos of the "process":
https://goo.gl/photos/KwGZ7Zx7XKo6sVf48