SUNDANSS
For my money, the
Lycan is identical to the old T71, before the split into two T71's. Actually, I don't know the difference between the T71 CMD versus the T71 TACO, or whatever the other one is called. Either way, the Lycan is fantastic if you are comfortable with light tanks. Good, not great silver generator.
The
Revenant is basically a not-top-gun Panther, the Tier VII German medium (it has the L70, not the L100 7.5cm); in fact, the gun is identical to the premium-matchmaking Panther/M10. So limited to a Tier VI gun, without the premium matchmaking, on a tier VII medium. In many situations could be a better silver generator than the Lycan.
Myself, if I didn't mind the L70 gun on my Panther, I'd go for the Panther/M10, and get the premium matchmaking, but that really isn't on the table I guess...

So Lycan versus Revenant? Easy call for me: Lycan.
The
Kaiju is a premium version of the Japanese Tier VI heavy, the O-I, but limited to the 10cm gun. I have the Kaiju and I prefer the 15cm gun on the O-I, so the lack of it on the Kaiju aggravates me.

It doesn't get premium matchmaking, but the gun is classified as a Tier VII gun, so really, its not a huge hardship. The speed is not great, and it is a huge target, with troll front armor, but TOG-II-like slab sides that are easily penetrated. Played right, it can be blast, and if its top tier and the circumstances are right, it is a holy terror.
The
Gorynych is another premium version of the Soviet Tier VIII premium heavy tank, the KV-5. I have the KV-5, and like it a great deal; the armor is troll, pretty much from all angles, and with the premium matchmaking: you never have to shoot at Tier X tanks. Which is good, since the penetration of the standard rounds on the KV-5 gun (ZIS-6), is actually a little less than the Kaiju 10cm, but both are classified as a Tier VII gun. Top tier, and played right, it is a terror, especially on a limited mobility map (like Ensk, or Himmelsdorf); no one wants to fight a KV-5 in tight quarters. Little known fact: the KV-5, as an 80-ton tank, is a fearsome rammer: I will _always_ make a ram attack on an enemy tank down a slope.
Kaiju versus Gorynych? Personal preference, really. Though if you don't have a premium matchmaking Tier VIII, and everyone should, then the Gorynych is decent choice.
The silver earning potential of the Gorynych will be higher than the Kaiju, simply because of the tier difference.
The
Hollenhund is a German premium variant of the American M41 Bulldog: a painted version of the leKpz M41 90mm ; both are Tier VIII light tanks. The gun on the Hollenhund is actually better than the top gun on the American M41. All the usual light tank goodness of the Bulldog, with a better pen gun and higher alpha damage. Literally nothing not to like.
The
Dragon is a Chinese premium variant of the already premium Type 62 light tank; comparing the Type 62 to the other tech-tree Tier VII Chinese light tank, the WZ-131, the Type 62 has a buff'ed version of the starting WZ-131 starting gun, the 85mm. The rate of fire is roughly 11 rounds/min, versus the WZ-131 ROF of 9 with the same gun. So all the usual light tank goodness of the WZ-131, with a better rate of fire (but less pen/alpha, and somehow better aim time). Again, nothing not to like in comparison. A top-package WZ-131 has better pen and alpha, and slightly faster, but the DPM on the Dragon is higher (assuming all rounds pen).
So Hollenhund or Dragon? Purely personal preference; they are both somewhere between good and fantastic.

I guess its a question of which fits better in your garage: tier VII versus tier VIII, German versus Chinese.
Just my three kopecks... :superdrunk: