I have three routines that I rotate on a monthly basis but I suspect that it's mainly superstition that it actually works. In the end it should turn out identical to having all levels the same all season. My results were fairly even all season, I started to concede more goals but I kept scoring and I estimate that 90% of the goals I conceded was "scripted" as we say. Most of the goals I conceded against Top 4-5 teams didn't feel scripted as I made some serious defensive errors from time to time.
On the bright side, I had in total 7-8 penalties, none against, received a fair amount of FK's and didn't see more than a few keeper blunders. I don't count all near post goals as direct blunders, but there was some weak positioning going on but not much.
In the end, the thing that annoys me is that the midfield pressure becomes too much for realism and constant over 90-120 minutes. It removes a large part of the pitch which force me (the players) to resort to unrealistic football to overcome the unrealistic opponents.
Personally, I'd prefer the game to respect my speed and difficulty settings and I'd pick an even weaker team if things became too easy. Superstar should be more or less identical at the start of the season and the end of the season regardless of how your results are. Same with speed setting. You can feel the game tweaking gradually, and if it can't stop you with sensible means it doesn't seem to have a sensible limit to how far it can go. Towards the end it was challenging to string three passes together at the back, as the AI strikers were so fast at moving that they were upon my players almost before I could control the incoming passes.
Forgot to add;
I played on Superstar, 15 minute matches and -1 speed setting. Home made OF, no 3rd party additions and default team count.
I am going to try a new ML season on XBOX360 at Professional now with nearly identical OF. I probably should go with Cardiff to compare but I think I need a change to keep it interesting. I got Cardiff with a "/random 20" counting from the top of PL table and I'll do the same now, re-rolling if I get 4 or less.
PS. I also forgot to mention that my players with high 70's and more stamina didn't seem to have problems playing full 90 minutes. Before the patch a player with 90 was knackered at 65 minutes, so there's a huge change here. I'm sure everyone has noticed it by now though.
EDIT: No sooner than having said that I didn't think the keepers were especially bad, I experience no less than four goals going in from nearly dead angle at the near post. The keeper just sits down and the ball goes nearly through him. Weird. I took Superleeds' advice and changed my training further and it seemed to help somewhat. I also tuned down my own team's frontline pressure and it seemed to calm the CPU somewhat as well.
EDIT2: I couldn't be arsed to hook up the XBOX360 so I started another ML from scratch on PC with a new team. This time I'm playing with Spurs and the game actually seems harder despite the fact that Spurs is a stronger team than Cardiff. My players doesn't get much heart boost from wins, opponents harass me like there's no tomorrow and Lloris makes one howler after another. I'm currently ironing out 1 goal wins 2-1, 3-2 and 1-0. Still playing with the same settings as before but with a new formation, 4-4-2 as opposed to 4-2-3-1 with Cardiff. It seems to me that the difficulty in this game is backwards. I'd think that it was logical that using a better team would make things a bit easier but not in PES apparently. Crystal Palace simply played me off the field just now, although I got a lucky 3-2 win after two goals in injury time, including a weird penalty situation. Since my player's heart level is around yellow and green, they feel mostly like they're running in tar while it feels like every single opponent has ultra red heart level as they are extremely agile, aware and confident on the ball. I feel like Greece during Euro 2004 at best even against bottom sides. Adebayor is a beast for me though, seriously overrated in this game. ML does not feel like PES2014 exhibition match at all, and it's exclusively a bad thing. Too many poorly implemented RPG-ish background effects and too little sensible AI tactics going on. AI's only approach is to apply massive pressure for 90 minutes and they never seem to tire even the slightest. There's hardly any difference between playing against Barcelona or Hull except the kit colours and that the better teams' strikers score proper goals rather than massive GK howlers.
After roughly 1.5 ML season with patch 1.07 I've come to the conclusion of retiring the game for a while. It's somewhat fun and much better than its been in years but it's also very, very arcade-ish as already mentioned. What I dislike about this game all boils down to what I disliked with PES2013, PES2012, PES2011 and so on which is the stupidity of competition modes. It is the same issues that I have with games like FIFA as well, so it's not a "goodbye" post in any way. There are some "new" annoyances as well, such as my own players getting in the way quite often, crashing into the player in possession making me lose the ball. AI does not seem affected by inertia in the slightest, I never really noticed that in exhibition though so might be an added competition "AI cheat". Heart feature seems to boost too many stats. In my opinion it should only boost/nerf accuracy and tenacity and not by very much. There's simply too much "background stuff" directly affecting the matches and it's largely in a negative way. For example, if the AI thinks you are performing too well it stops all but the most basic team movement for your team - no more initiatives and runs from your teammates on their own. The AI should consider the human player's team strength on paper and recent results when picking a match plan. Not scrap football in favor of a fake sense of challenge and it feels a bit coincidental when you succeed. Goal variety is very good though, I've scored a lot of really nice and some unexpected goals but I've also missed some insane chances like open goal which feels like AI putting the foot down on the goal tally to be spiteful. I didn't lose a single match though, but it didn't look much like football towards the end either. It was comparable to WC finals on Microprose Soccer with better graphics and animations (for those who remember that insane tackle-fest).