I cannot speak for the Regal versus Streamline, but I can speak for the Air Wolfe MCT versus the Royale 400 or the Independence.
The walnut stock on the Air Wolf is finished shinier than my Royale stock and if that glossy finish is your thing, it is a bonus; however the Air Wolf stock has serious QC issues regarding the cut-to-fit around the rifle action. In fact the stock is cut so poorly, it takes two grown men several minutes of working, tugging and pulling to get the stock off without damaging anything. It is that tight. And no, it is not due to wires or any part of the action, just a poorly cut stock. When putting the stock back on, a person must be extra careful to get the front-to-back fitment perfect, or the foster fitting cap will be nearly impossible to remove for tank refills. The FX Royale stock has a much less glossy finish, but it is cut significantly better and more accurate than the Daystate stock. Plus I would have to give the FX stock the edge for ergonomics. The Royale comb area is flatter and more useable, along with a slightly better grip-to-trigger fit and feel.
I have done some trigger work to all three of my FX rifles, but that work is minimal. With that said, the FX triggers definitely have a higher quality, more solid feel. Please do not confuse high quality feel with trigger pull weight, as the Daystate trigger stock out of the box is still a few ounces lighter that any of my modified FX triggers. With that said though, the Daystate electronic trigger has this vague, fluttery feel that includes an occasional hang up just at the beginning of the 2nd stage; which sometimes makes finding the beginning of the 2nd stage difficult. And yes I have done some adjusting on it. If it were not for this occasional vagueness, I would rate the electronic Daystate trigger a little better than my slightly modified FX triggers, but for now I will call the FX triggers on my rifles just a little better. In the near future I am going to go into the Dayate trigger and figure out what is gong on with it. Once done, I expect that trigger to be the best!
The shooting cycle time of the MCT Daystate is noticeably faster than any PCP I have ever shot. Big bonus. My FX Royale with its 400cc tank and regulator has a notably flatter shot count, meaning less variance in velocity. The overall shot count for both rifles when fired at just under 20 ft-lbs is nearly identical. Power adjustability, range of adjustment and how easy it is to adjust - the Royale and Independence have the edge over the Air Wolf.
As for noise levels, the Air Wolf with its included full length Hugget shroud setup, is noticeably quieter than my 3 year old Royale, but very similar to my Independence with its full length shroud. Very close!
Accuracy is tough to call. The .22 Independence has been and is still the measuring stick in which we compare other air rifles to when new or tuning customers rifles. The Independence is NOT pellet picky, as it will shoot nearly every quality pellet well and several types GREAT! The .22 Royale is just a hair behind it and it is really nit picking to not say they are the same, but for some reason the Independence is just a little bit easier to shoot those perfect one hole groups with. The .177 Air Wolf is an enigma when it comes to accuracy. First it was difficult to find a pellet it liked. Yes it is pellet fussy. Go figure. Second, even after finding a pellet it seems to like, it struggles to put great groups together off the bench. But shooting it outdoors, off shooting sticks at knock-down targets while practicing for FT competition, it is almost difficult to miss. I am struggling to figure this accuracy weirdness out, but again, outdoors shooting at distance the rifle is easy to shoot accurately.
My FX Royale has well over 24,000 rounds through it, the Independence just exceeded 31,000 and the Daystate Air Wolf which I just received 2 1/2 weeks ago has nearly 4,000 rounds through it. In addition, my FX Boss has 8,000 rounds through it. The Boss exceeds any thoughts or expectations of what ever I thought long distance, large caliber accuracy could be in an air rifle.
All of these rifles are a pleasure to shoot. The Daystate does cost hundreds of dollars more than the Royale, so it does upset me about the stock issues. But due to the electronic setup in the Air Wolf, it is extremely easy to shoot. Almost an emotional experience. All of these rifles are great and a person could not go wrong buying any one of them.