I have both and love both. I would say almaBb can be dressed up or down, especially the leather versions. Bal mini city is more casual and edgy. I wear mini city a lot during daytime on weekends but I always take my Alma out to dinner and fun afterwards
It really depends what you are looking for. If you want a versatile bag, go with AlmaBB. If you already have a small bag for more formal settings and want something relaxed and cool, go with mini city.