I've been wondering.. i have the Black GGH Work and am wondering if i should now change it to either a city or a part-time? I love the fact that the Work is a big, big bag.. However, i love the shoulder strap of the city and part-time.. I'm about 5'8" and pretty slim so i dont know if the big work or the city or part time would match me... i'm so confuseddd! what do you think i should get?