I got 2 of these, one in the Armor plastic and the other in Storm plastic. I will say its more like a thunderbird in the storm plastic, and CD1 esque in the Armor plastic. Didn't quite fill the slot it advertises, but this thing goes straight for SOOOO long with a nice gentle fade at the end in the storm plastic! If youre looking for something with a bit more turn, the Armor plastic offers just that

Flight numbers don't mean everything but they should give you an idea of how a disc will fly. It's rare that a disc gets ALL 4 numbers so wrong. The same numbers as a PD but flies like a TL3 or even an Essence. Very flippy which is fine but not at all what I expected. This seems to be a thing with Viking based on my sample size of 2. I have a Storm Valhalla that flies like a PD2, so it's off in the opposite direction.

From other reviews it sounds like the stability experienced has varied a bit (on different runs?), but for my arm speed, the Fenrir in Storm plastic didn't seem too far off from the flight numbers, relative to other discs I compared it with in field work. The testing was in pretty windy conditions, though, so I'm not sure if I was getting flat, straight flight for as long as I was due to good throwing (I'd like to think so : )  ), or because the turn/fade should actually be tweaked to reflect a lower stability. I'll have more chances to determine that with time, but either way I think the disc will prove suitable for experienced players once they determine for themselves the nature of its flight for their throwing power/mechanics. The quality of the Storm plastic seems good, and it's easy to grip and release. However, the first time today I had a Storm plastic disc take a hard hit: It got pushed out of bounds by the wind and smacked pretty directly into a cement curb, and I'm (very) sad to say it appears to have changed the turn factor of the disc from 0 to about -2.5 with that one hit. I'm surprised it changed that much after a single hard hit. That's kind of challenged my faith in the durability of the Storm plastic.

The Fenrir in storm plastic is not nearly as over-stable as the flight numbers indicate.  I have found that this disc performs more like a Innova Wraith (S11 G5 T-1 F3) or an Innova Mystere (S11 G6 T-2 F2) than a typical S10 G4 T0 F3 disc.  I have thrown this disc mostly RHBH with a flat release angle expecting a reliable fade throughout the final stages of flight but have actually seen a lot of early turn which at times will turn over entirely and cut rolls.  To get the most out of the disc, I have actually been throwing more on a hyzer line to ensure stability (not a common play for a T0 F3 disc).  I have also been a little surprised at the amount of glide the disc has (probably due to the early turn in the flight).

The storm plastic is extremely durable and provides adequate grip in most conditions.

Due to the misrepresented stability, this disc may actually be somewhat beginner friendly for players looking to add a little a little bit more distance to their game.  

So first off, storm plastic is great. Like Innova champion but more grippy. I got this disc to be a more glidey firebird type but I gotta say, this disc loves to turn over for me. I'm no bomber, but when I rip it flat or with some hyzer, it flips up and stays right. It glides for days but I would more rate it to be a 9, 5, -1.5, 2.