HSPA may be viable in most of the world today, but what will it be tomorrow? It seriously looks like the USA may go LTE for it's convergence protocol as both Verizon and AT&T are looking for 4g protocols.

As long as the n9x0 is "not a phone" you will still need a shiny 3g+ device in one pocket anyways, you might as well tether. This will provide you with all the access you need and be future proofed ( especially if Nokia used it's weight on the N series phones to make tethering easier * hint hint * ).