are you sure its a literal 5 minutes and not "this feels like 5 mins"? Cuz yeah 5 mins is fucked up and something is wrong. HD should be around 60-120 seconds to load a level. SSD's can drop that to 10-20 seconds. So while SSDs are much faster, 5 minutes is way, way, way too long. Try defragging your drive, and deleting BF4 and redownloading if its still slow after that.
with all the crashing everyone experienced for so long it wouldn't be surprising if some people got some of the data files corrupted.