Even a decent 4G wireless network cannot match the speed and reliability of your cable internet service. If you do ANYTHING at all that will require a good fast connection for decent bursts of bandwidth, cable is the superior option.
I have tried 4G hotspots AND 4G Air cards from both VZW and AT&T. When there is a strong 4G signal present, both work amazingly well in spurts, but are very inconsistent. You get a great, fast connection for 10-15min, then it'll hiccup for a few minutes. This happens over and over again. The Verizon Mifi unit is especially susceptible to this problem.
It can get to be very frustrating when downloading updates, or uploading photos, etc.... I breathe a sigh of relief when home, connected to my Comcast account.