I'm just gonna put my opinion across here because this is really quite interesting. I popped it into my PS2 just now, and it's been a while since I last played Fusion so I'm going in with a fresh mind.

The first thing I'm noticing is the significantly wider tracks, which are quite interesting.
It allows for some strange racing lines compared to the norm, mostly hovering right along the centre line on straights to avoid adding unnecessary time to traversing over the other side of the track to take a corner.
But considering the apparently slippery physics (read "next to no traction in comparison to literally any of the other games"), it's good to have a lot of room.

The next thing I notice is the number of ships. A solid 16 pilots on track at any one time, the most since 2097/XL and 64 introduced the Piranha prototypes.
No wonder they need the extra room on the tracks - XL had heavily scripted groups of ships as you progressed up the field, but with this more fluid system it's easy to get a pile up of up to 5 ships regularly to block parts of the track.

Here's the part where it starts to get dicey for me. With each activity you take part in, you and the rest of the grid gain a new weapon to blast each other to pieces with.
Great, that's good, I was looking for more destructive power to force my way through the pack.
Except I played through some Van-Uber Super Weapon Challenges before beginning the AG League mode.

Which means I have no credits and about 3 or 4 Quakes flying down the track at me per lap. And I'm trying to fly a Van-Uber with the duff shields, with a high chance I won't be surviving a single lap.
So I'm forced to try a different team. Van-Uber, it seems, is quicker off the start line but with the unfortunate drawback of being made of 'effing glass. Let's try G-Tech, maybe that'll help.
---3 laps later---
I just came in first place with Naomi Turner of G-Tech. Of 16 ships, only 7 made it to the end. Namely Tigron, Xios, EG-R, the other G-Tech, Auricom and Feisar.
My concerns were made clear, in that as soon as Quake unlocks, unless you have some cash behind you, your hopes of flying Van-Uber are dashed quite spectacularly because the game will mercilessly punish you.
Aside from that, think I'll be trying out G-Tech for the rest of the league (using a Feisar at this point is too blasé and perhap inadequate in the speed area).
Plus they aren't as bad for handling as I expected, and the game seems to be rewarding the high speed, firepower and shield ratings anyway.

That seems to be the big issue many are bringing up here - the teams are completely unbalanced.
Even when comparing the ships within their own performance tiers (Beginner - Feisar, Van-Uber, G-Tech / Advanced - Auricom, EG-R, Tigron / S-Tier - Xios, Piranha), there are clear winners and losers, what with Piranha being just that little bit more perfect than Xios.
Uber could've done well in any other league, heck they even did well in FX300 Pure before giving up for reasons unknown.

Maybe it's the huge emphasis on hard hitting weapons and half-decent shielding that's the issue, I don't know.
Maybe it's even the departure from familiarity, attempting to bring too many new names while ditching some of the old favourites (team allegiances, yo).
And then the wrong type of homage to 2097/XL by having every other team falter to "INTRODUCING!! Another illustrious god-mode ship, coming at you from the one-and-only Piranha!".

To summarise:
It's got it's good parts, I'll give it that. The scenery is gorgeous, the tracks are memorable and I love the unpredictability of the open-ground sections of the track (though ice physics on anti-gravity makes zero sense...)

It just too easily descends into chaos.
With that many ships on track and so many weapons, eventually it simply comes down to who has the bigger guns and the stronger shields to survive the next lap.