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In general though Tokamaks are a proven technology - we have impressive and optimistic results which look good and we can extrapolate that to larger tokamak vessels and expect success. Whereas there are a whole host of relatively immature technologies such as Focus Fusion, General Fusion, Polywell etc. and even the more mainstream Inertial Confinement experiments aren't as mature.
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Regarding Todd Rider's thesis - he worked on both thermally-equilibrated and highly nonthermal distributions. The takeaway in either case: P-B11 fuel would bleed off a lot of its energy due to Bremmstrahlung losses, more in fact than it produces from fusion (by a factor of around 1.75, as I recall). A nonthermal distribution would reduce this factor, as a greater fraction of your distribution could actually fuse (in a thermal distribution, it's really just the high-energy "tail" of the Maxwellian that fuses), but it's still over-unity (something around 1.2 for P-B11). Add to that the requirement of energy input to maintain the nonthermal equilibrium, as the plasma will relax very quickly to a thermal distribution, and you run into problems. This effectively kills concepts like a polywell or fusor, which require active maintenance of the nonthermal distribution. A focus device, which is essentially just a magnetic-pinch implosion, could potentially avoid that maintenance problem.
As it is, the tokamak has demostrated consistently good performance, but since things like focus fusion are (a) built on a much smaller scale and (b) often privately funded, I can't think of a good reason not to research them as well - I certainly won't hold a grudge, because hey, we'll be making fusion work.
I think it is right that ITER and the experiments supporting ITER (such as Alcator) get the lions share of the funding when the evidence leads us to believe they are the most successful.
this leads us to the problem we're hitting for current budgets - if you take a look at our site here you can see ITER's funding basically eating the domestic program. ITER is the best bet we have moving forward in fusion, but the loss of our domestic program would cripple our ability to produces scientists in the future working on these projects, and would throw away a half-century's worth of technical expertise designing, building, and operating these machines. Once that's gone, you don't get it back - basically, we're deciding now whether we want to be selling fusion power plants, or buying them.
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