There couldn't be much more of a stark contrast between the post-paid Telstra Mobile Wi-Fi 4G and the significantly cheaper Telstra Pre-Paid Wi-Fi 4G hotspots. The post-paid product is small and elegantly built, and the prepaid product is clad in extremely cheap-looking white plastic.
The post-paid hotspot, which, like many Telstra-branded budget products, is a rebadged ZTE MF91 — has a sharp monochrome LCD display, while the prepaid hotspot has a garish, low-resolution colour display that relies on scrolling information on the screen, something that's highly annoying. The white plastic back of the Telstra Pre-Paid Wi-Fi 4G is rigid and tough to remove for inserting a SIM; if you were sharing a SIM between the hotspot and other devices — as we were during testing — there's the very real worry that the brittle plastic will simply shatter one day.
Telstra's 4G network is the backbone of the Telstra Pre-Paid Wi-Fi 4G, which means, like the post-paid Telstra Mobile Wi-Fi 4G, it's got access to the (at the time of writing) largest 4G long-term evolution (LTE) deployment in Australia. If you live outside a capital city (or Newcastle/Gold Coast), Telstra is your only 4G choice, and the Telstra Mobile Wi-Fi 4G is the cheapest way for you to access the network in terms of straight computing devices. Given that most smartphones support some form of tethering/hotspot functionality, it'd be feasible to get an even cheaper solution with one of Telstra's prepaid ZTE 4G smartphones, such as the, but you'd have to carefully balance overall battery life so as to not end up with a flat phone.
The Telstra Pre-Paid Wi-Fi 4G's inbuilt router configuration page is, like the device itself, on the rudimentary side. It shows the basics well, but there's no elegance to its UI design. That may not matter beyond perhaps changing the default SSID or password settings, but if you're a tinkerer, it's quite bare bones.