For any in this league who have not yet experienced 4.5, be ready for some significant changes and take it into consideration when it comes to your roster decisions in early FA, trading, and draft. From what i have both seen & experienced among the 12 teams I currently have, there are several consistent results with 4.5 vs 4.4.
QB ratings are down an average of 20%, interceptions have substantially increased. Ive seen league leading QBs go right down the tubes in 4.5, to sub 70 ratings. I had an LC winning rookie QB with a 90 rating in 4.4 go down to a 46 rating, 23 interceptions in 5 games, and had to bench him by game 6. Your QB will be much more dependent on the overall rating and ability of your receiver group (WR/TE/RB/FB) and play selection.
Sacks will be fewer, an average of 1/2. The blocking algorithm has been upped for the OL.
Secondary coverage has been improved in addition to the improvements in 4.4, especially for CB1,2, and 3(Nickel/Dime). The Bump attribute has been increased in the algorithm. Speed is still a +, but not as dominant as a key attribute for secondary as before.
Pass Interference has become a game changer, as it can do in RL. They tend to happen to one team more than another per game and can kill your defense. The Discipline attribute for DBs & LBs may have increased in importance to reduce this problem, Ive never made that a major consideration before, but PI penalties can be devastating. So, worth considering..
There are several other factors/considerations, please post your own observations & experience with 4.5. cheers! gdb