personally i think it's a bit hard to renegotiate after having rented for a year. but like you said yourself, there are other available units there as well, you may look for other options if you fail to negotiate to an agreeable rental.
but if you ask me, i'd like to know if the landlord gives you any trouble during the past year. i know some landlords who are pain in the ass, if yours is not a fussy type, i don't see why you should risk to get a new landlord and new unit. i know i don't mind paying a bit more to have a good landlord.
my girlfriend rented a condo which was quite cheap in comparison to other units in the same condo, but the landlord's a total biatch. when she moved in she found that all the light bulbs were changed to cheap second hands, all rosak within a couple of months, complains that the toilet's dirty (when it's a lot cleaner than when the condo was passed over), doesn't want to take responsibility with the water heater and pump (the water pressure is very low, it's extremely hard to take a decent shower), etc.
she's looking forward to renting another one after the contract ends, doesn't matter if it's more expensive as long as the landlord's okay.
moral of the story: pay peanuts you get monkeys.