I guess it all depends on what's important to the individual and how theyre getting their phone. Tethering isn't important to me as in my opinion it's impractical. I have a separate 3G plan for my iPad and I prefer it that way. I also don't by phones on contract any more and haven't done so since I got the iPhone 3GS. I bought both my iPhone 4 and 4S as well as my 5 SIM free off contract.
Further more we can't make judgements on the performance of EE's LTE network until its up and running and people have used it. Also Three's customer service from what I've heard is the poorest of all the networks. Also although I've not used it where I am I have spoken to several people who have and according to them the performance isn't that much better then the other networks here.
I'm not sure what I'm going to do yet but either way I want to leave O2 who I'm currently with as their speeds and network signal is quite poor here. I'm not really convinced Three is a worthwhile network just because its cheaper and there are some people who are getting good speeds with them.
I'm more inclined to go with EE/Orange/T-Mobile either now or wait until they announce their LTE plans and what pricing they are and what level of data they include. I also use my iPad just as much as my iPhone for data purposes so I don't completely rely on my iPhone.
I was the same not sure about three, 1 bar of 3g = 2mps max iv got is 7.8 mbps in town, id reccomend them on a month contract,