How does pocketwifi work with an ipad mini?

Particularly travelling in Europe, how does it work, how do you get it, how much does it cost? Is it a better (or at least ok) option than paying for a cellular capable ipad mini and buying a sim card? Will it work ok on an older ipad mini that is wifi only?

i had pocket wifi in oz and i will ALWAYS do this - so good, always perfect reception and so much cheaper plus you can connect multiple devices. the Voda one i have for oz is just prepay - would never go back after discovering this after my data on my iPhone just wouldn't work through the normal network randomly one time