All this their network issues dem, na why I never still buy Glo sim, though na them be the best for data offers and Dem sabi customer. But that their network issues just too much, the worst tin wey go happen to person na make e go use Glo sim as em bank ussd transfer sim, because Glo network com join bank own, that na very big network combo
. Just as Mr Charles_Tim don talk, e go good make you try all the sims but I go advise make you nor even waist your time try Etisalat, because na them be the worst. Me na Airtel I dey use, and I'm satisfied with the offer wey Dem dey give me.
something times all this network issues dem na from our phones, I dey experience some kind time wey my phone network go just dey slow or nor dey even work sef wen I sti get data, so until I put the fone for airplane mode come commot am, before e go come dey operate normal. So most times you fit dey try this technique.
The the second technique wey I go recommend na say, if your fone network dey slow down, while you get data, just go your call side for the phone as if you wan dial number. Den dail *#*#4636#*#* you go come see some options, pick phone information, then just go down to where the you go see preferred network select LTE which is 4G, then just minimize go back to your browser or wattin you been dey do, you go observe say the network go come fast.
Follow the pictures direction and you'll be just fine.
Note: this one nor dey work for all phones especially Samsung, though I never try am for iOS(iphone) but e dey work for other Android device wey I don try