Takes about 5 times longer to level. items are not levelled. bandits are more likely to be wearing cheaper, rougher banditty stuff etc. if you care to step into some of the marauder caves etc you might be rewarded with better gear but you'll also be dead
its designed so a level 1 - 10 player generally runs for his life.... a lot!
however levels are fixed. so if you are cautious, work thru the guilds and quests and slowly level you will overtake most characters.
Oscuro does however make a comment about being at least lvl 20-25 to go into an oblivion gate, even then its hard going.
its a hardcore rpg that rewards hardwork.
you could use OOO lite which enables you to use different plugins for levelling speeds etc amongst other optional OOO content.
i started my first character with OOO. the game was better but being as i was new to oblivion i got impatient. im going to run my current lvl 30 character thru every quest then start again with OOO. a lot of people whine about the broken level system but i've not had any trouble. levelled loot means the money pours in past lvl 20. every bandit is in glass or daedric and the scraps are fun. with good enchanted armour and powerful spells you soon become the main player in the game. i just love it all