So I've just been using my brother's new Wi-Fi only iPad the past few days. Yesterday, FedEx delivered my iPad 4G+Wi-Fi (Verizon). Looks like it'll be well worth the extra expense. At home, SpeedTest showed 20Mbps down/20Mbps up. At work, 15Mbps down/3Mbps up. Really awesome speeds.
Heck, the first few minutes, I didn't notice I was still on LTE while downloading apps. The speed I get on LTE is just the same as what I get from wi-fi (crappy, supposedly N router, wired is faster).
The downside to all that extra speed? I quickly burned 1GB in just a few minutes without even noticing.
Now we'll see if I can continue getting the same speeds when visiting the grandparents'.