As you said it really depends on your use case. For me tethering is a piece of cake and my phone has unlimited data for basically free. For $15 a month I would get what, maybe a gig of data? So that's $180 extra a year for limited use plus the extra cost of the LTE tablet which ain't cheap. As far as battery life I can carry 2 spare phone batteries in my pocket and go for days.
That being said, if I were a road warrior and wasn't concerned about how much unlimited data would cost I'd probably get the LTE model just out of convenience.