I really agree with you. For me Mahrez will have an incredible next year if he signs for us. Some posters tell you he isn't better than for example Raz. But there are 3 things you have to answer first.
1. When was the last time you have seen fully motivated Mahres fighting for something? The year he won Player of the year, and title for LCFC. That season there were times he was almost unplayable. Year after his team was shit, he fought for nothing, but he still made some stats. Last year he just wanted out. I bet he wasn't giving 100%, as was his team. If you have a dream, you fight for PL, CL all the players up their game, if you fight for mid table, and wants out, and your club blocks you, how could you play and give it all week in week out?
2. How were LCFC attacks built? How much of the ball they had, how many chances they created, how much they bossed their games? Even in the season they won PL, they weren't even in 40% as dominant as City are every week. Even taking that into consideration, you can easily compare his stats to top top players in better, more dominant teams. How many goals/assists he would have in team like City this year?
3. The most important question for anyone stating he won't improve our team: is he worse finisher than for example Raz? ehhhm not. Maybe he is worse assister? not really. Worse dribbler? I really thing he is one of the best 1 vs 1 in world football. Maybe he has worse first touch? no he has not.
He has decent speed, not as fast as Sane/Raz, but really decent, can score from distance, is great finisher, can assist, and can unlock packed defense with his 1 vs 1 + he was begging for a move for 2 years, and he doesn't break under pressure - in LCFC tittle winning year he was their main man, and the better opposition were, the better he played (I still remember goal against us, when he left our 2 players in blocks and his shot left Hart on his feet). He will be fully motivated, hungry as ever, fresh with no WC, PL proven, and has all raw attributes to really step up his game to world class level as Salah did this year. He just enters his best years, and will be on his 200% self to show everyone why he wanted to be sold to one of the top teams 2 years ago, last summer and in january.
I am not saying he will end up our new best player, but look for some clips from his POTY year, and ask yourself: is it really impossible that this guy could take Raz out of the team? I can easily imagine that, even if I love Raheem and think he is great.
Mahrez is pure class and will suprise few on here.