Personally, I have found very mixed results
Reason to upgrade #1 - All the new cards have 99 ratings and I want to get the best overalls
Counter argument - Apparently most attributes have "thresholds" so 90s play the same as 99s. The only rating that really matters is speed, but with theme teams, 95 speed players with boosts are just as good as base 99
Reason to upgrade #2 - All the new cards have 0 AP abilities
Counter argument - Abilities are SO SO SO inconsistent this year. Even the more consistent ones like angry runs/knockouts dont work as described. I have seen my angry runs RB easily tackled by DBs without secure tackler/tackle supreme. I have also seen my secure tackles/tackle supreme players consistly miss secure tacklers
Runstopper X Factor/No outsiders/inside stuff barely works. Ive seen my 99 overall DBs with KOs not even attempt to go after the WR, but stand there like statues
Also, what good are abilities if your CPU players dont know how to use them. My Secure Protector ends will try to block the center DT, leaving my opposing DE a clear path to the backfield...so I dont get to to use secure protector
MidZone KO seems to be the only ability that consistently works.
Reason to upgrade #3 - the new cards have built in X Factors as abilities
Counter argument - It seems XFactors as abilities are not as strong as the original X Factors
Outside of Warren Sapp, Unstoppable Force has done nothing on any of my players. John Randle - nothing, Micah Parson - nothing, Mercilllus Whitley, I had to add DoN and Edge Threat Elite.
Also, all the DBs with Universal Coverage, it doesnt matter if they cant cover anyone. My 99 speed DBs still get burned on deep routes even if I dont press, so I cant get a KO. Often times my DBs will run to the wrong zone spot, so theyre not in position to get a KO. Plus half the time, my DBs wont even jump, even if I use them and press Y to jump
Reason to upgrade #4 - I want to counter the meta cheese plays
Counter argument - The cheese players will always work. You can put Dual Threat/Reinforcement on all your DBs, yet they will still get pancaked by lilttle WRs like Tyreke Hill/OBJ on bubble RPOs. It seems like on a bubble RPO, any WR's pass block goes up to 1000%
The stretch runs will always work, because half the time your CPU defenders will 99 pursuit will not even attempt to go after the RB
Conclusion
Overall this game is just so inconsistent, which prevents it from being a good product. I give MUT 24 a 6/10