iPad with cellular is ok for me but I don't use it very often because I have grandfather unlimited data plan on my iPhone
same.
i bought an LTE model not b/c i wanted to pay to constantly have an LTE plan activated on the iPad, but rather i wanted the option to.
i have an iPhone 4S, jailbroken, grandfathered unlimited plan. i milk it every month (i use ~6GB per month). most of the time when i am out and about i tether my iPad to my iPhone 4S.
however for long trips in the car or when i need a mobile connection faster than the 3G on my iPhone 4S, i will activate the LTE plan on the iPad. also, the hotspot on the iPad LTE lasts MUCH longer than on my iPhone so when i know i won't have access to an outlet for a while i will activate LTE for that month.
most here are talking about the Mini though, i bought an iPad 3, 64GB LTE-Verizon refurb for $679