3G vs 4G Help

I'm looking to switch over from Bell to Public Mobile, however, I am having a hard time picking the data option for my plan. The talk and text portion of the plan is going to be Province Wide and Global. My two main options for data are the 12 + 6gb on 3G over 90 days and the 3+3gb on 4G over 90 days. I'm not sure which one I should pick. I know that the 18gb one is basically 6gb a month which is great but it's on 3G. On the other the hand, the 4G one is basically 2gb a month which significantly less. So I was wondering is the 3G 18gb/90 days a better option despite being slower than 4G 6gb/90 days? Also, I was wondering is 3G noticeably slower than 4g? I should also mention that I'm not opposed to the 6 +3gb/90 days on 4G as well but I prefer the two options mentioned above. Any help would be greatly appreciated, thanks.