If they offered unlimited at a decent price then yeah I wouldn't mind it. It wouldn't hurt to have the coverage incase I needed it that one particular time... But for now I am covered just fine. I don't travel that much so that is my saving grace.
Although.. I'm not saying I won't ever go to another carrier... One day it'll happen. I'm just a believer in carriers are very dependent on area so.. The myth that T-Mobile is bad everywhere isn't true

... But I am only with them mainly for the unlimited data... If i had good wifi at work I wouldn't need unlimited... Since outside of work I barley use any data. I'd probably be on AT&T.. Or Verizon.. Leaning more towards AT&T though.