There is a problem in Skyrim leveling system compared with previous games. It is because of the perks, we have to choose one perk in every level ups.
Let say i level many skills to 30 such as Two Handed, Alchemy, Speech and Heavy Armor...when level up i only can choose one perk. If i choose Two Handed, i must wait 3 level ups to choose other skills perks and during that time i don't gain benefit from level 30 skills that i don't choose the perk earlier
Isn't that a problem?
In Oblivion i get every benefit from skill level when it rise to certain level automatically, but in Skyrim no matter if having skill level 100 it don't giver any benefit except for few skills such as smithing to upgrade weapons/armor but not to made them.
It is hard to choose which perk, if i choose this, i won't get any benefit for others in few level ups while i also need those perks in that moment, but when reaching level 40 and above it doesn't matter anymore because it already too late and my character have explore 80% of the map and complete most of the quests