6th Gen Flygon or Goodra?

Heyyy! I made another thread similar to this, but I need help in terms of team building for Pokemon X.

Here is my team:
Delphox (Fire/Psychic)
Vivillon (Bug/Flying)
Mienshao (Fighting)
Aurorus (Ice/Rock)
Sylveon (Fairy)

I can't decide which dragon pokemon to add to my team. Initially, I had planned to have Goodra, however, Flygon seems increasingly tempting.

I'm going to list a few reasons why I would benefit from having each Pokemon on my team, and you can help me decide!

Flygon:
-Has greater speed than Goodra, and my team lacks fast, physical attackers (other than Mienshao)
-Better coverage against Steel and Fire types
-Good for 3/4 Elite four members
-Can use Fly

Goodra:
-Bulkier (Although my team tends to be extremely specially defensive)
-Better resistance against water types (As that's the one type the team is the most vulnerable to)
-Better overall base states

Base stat wise: Flygon is the winner, as it's greater speed and attack is more of what I need for this team. Although, Goodra is overall more powerful.

Which one would be better suited for my team? Thanks in advance!

I vote for Flygon, mainly because it is pretty fast.

The moves:
It can learn U-turn for scouting, Roost for recovery, Earthquake and Dragon Claw for effective STAB, Crunch to deal with Ghost and Psychic types, Steel Wing to deal with Fairies, and Superpower when you revisit the Move Relearner. It can also learn Flamethrower and Fire Blast, though your Delphox benefits more from those moves due to its' STAB combination.

Another team muscle:
Since your team (aside from Mienshao) generally lean on the special attacking side, another physical attacker would be beneficial, as Psyshock can only hit so many physically frail Pokémon before you run into those who resist or are immune to Psyshock.

Goodra I think would be more efficient and versatile. It lacks the 4× ice weakness that Flygon has. Also Goodra is a mixed attacker. She shares the same physical attack stat actually with Flygon, in addition to having an even higher special attack. Goodra can be tailored more to your needs than Flygon who I would not recommend putting a special move like Fire Blast on.

Quite a few of the aforementioned moves for Flygon were TM moves. Goodra can learn some TMs that are also worth noting like Sludgebomb for coverage against fairies or Thunderbolt for the water pokemon that are a priority for you to defend against. It can attack steel types with earthquakes or flamethrower as well, and for more damage than Flygon on the special side. It can use Ice beam too. Moreover I think Goodra's movepool by level up would make your life in Kalos a bit easier than with Flygon.

Goomy can start doing damage with a stab special move like dragon breath by level 18. Flygon doesn't learn a physical stab move in XY until dragontail at level 45. Goodra would be completing its ENTIRE special movepool around this point, strong moves in base from dragon pulse to muddy water. Flygon can be a good Pokemon, but its definitely a pokemon to have patience training, because its doesn't get many useable moves until it is at the highest of levels.

Goodra also has access to the much higher base power moves like Outrage, and can remember it at level 1, and if. Flygon can't learn Outrage, the most powerful dragon move it can use in xy is Dragon Claw at level 55. Flygon also does not learn earthquake by level up, only Trapnich can learn Earthquake at level 55, if he evolves into Vibrava at any point before this he will not be able to relearn it with a move reminder, same goes for quite a few of his good moves.

Since this is for an in-game playthrough I think Goodra's faster growth rate is an asset that should be given weight.

I believe Goodra is the better choice here. Although it seems that Flygon is better in terms of speed, it is overall definitely weaker than Goodra. Talking from experience here, as every time I have used Flygon I got this frail dragon that sometimes can't even take out an enemy with a supereffective STAB move. Goodra however is a powerhouse and won't go down easily, not to mention that has a better movepool as well.