But I'm wondering if the better option is to simply get a iPad that is cellular enabled and using this as a hotspot for all my other devices.
Which option provides faster connectivity? Anyone do either of these? Any other thoughts?
I'm not particularly familiar with mifi, but I tether from my iPhone to my computer and iPad fairly regularly. Even though it doesn't match your setup exactly, I'll tell you a bit about my experiences, my setup, and quickly run through what I perceive as some pros and cons of the two setups you're considering.
Tethering from an iPhone shouldn't be any different than an iPad, and you can tether through three methods: USB to your computer (assuming you're using a Mac; not sure how PCs would fare), Bluetooth (works seamlessly with iOS devices, not sure about non-Apple), or WiFi (works with all devices). The iPhones are programmed such that they shut down the WiFi network after about 15 minutes of inactivity, requiring that you re-enter the sharing screen to re-broadcast the network, and then initiate a connection while on that screen in order to maintain the network. I don't know if this 15-minute limitation exists when the phone is connected to a power source.
Bluetooth tethering is much more convenient. Simply initiate a Bluetooth connection from one device to another and, as long as you left the hotspot enabled, tethering begins immediately. The Bluetooth connection stays on all day, until the devices go out of range or break the connection. As long as your devices use Bluetooth 4.0, a low-power profile (introduced with the iPhone 4S and iPad 3; everything later supports it), the battery drain is surprisingly minimal for leaving the devices connected all day. I would tether my phone to my iPad Mini from 9 AM to 5 PM or 9-6 and my phone's battery wouldn't drop below 50% (but I also wasn't using the phone for anything else).
USB tethering is a breeze. Plug the phone in and the Mac recognizes it as a network device within about two seconds.
Speed-wise, USB should be the fastest, followed by WiFi, followed by Bluetooth. I believe the Bluetooth transfer speed maxes out at 3 Mbps (Bluetooth 3.0 + HS maxes out at 24 Mbps, but I don't think this is what the tethering uses); for reference, most LTE services seem to give speeds of 10-16 Mbps. I am using an iPhone 4S (which is limited to 3G and does not support LTE; fastest speeds I've achieved on the phone that I've seen were around 6-7 Mbps), but I never felt that the connection on my iPad mini was any slower when tethering via Bluetooth than on the phone itself.
So, which is better: tethering from the iPad, or w Mifi device?
The theoretical benefit of the Mifi device is that it's a dedicated router with a battery of its own. You wouldn't need to worry about taking it out of range of your other devices, and you wouldn't need to worry about draining the battery of your iPad or being forced to keep the iPad plugged in all the time.
There are a few downsides, though. Based on a very quick look-over, the battery life for Mifi devices is rather poor (four hours). It would represent one more device to lug around, and one more device and charger to bring along on trips.
Assuming you have it on you regularly, the iPad is a much more versatile hotspot in that regard. The battery life even with tethering is exceptional, you'd already have the device on you, and assuming your phone is an Apple device, the charger and charging cable are likely compatible (for full-sized iPads, charging from the iPhone charger is painful, but the iPhone can charge from the iPad charger).
My recommendation ultimately comes down to your phone plan and your usage scenario. If there's no major difference in cost between devices and their data plans, then it's a matter of convenience. The Mifi device might be more convenient if you're only tethering at home, whereas an iPad would be more convenient if you want to tether on the go (assuming you usually have the iPad with you). The benefits of the iPad as your device increase further if you have more Apple devices that you would be tethering to, given how well they integrate together.
