Yes, and the differences are even greater. In general Oneworld's RTW products are cheaper (mile for mile, or segment for segment) than either Skyteam's or Star Alliance's.

As you can see, the three alliances have their geographic strengths and weaknesses. Oneworld is particularly strong in the Middle East, Australia and South America, but quite weak in Africa. Star Alliance is strong in southeast and south Asia, and in Africa and central Europe, but quite weak in South America and Australia; Skyteam is hopeless in Australia/NZ, in South America and intra-Africa but pretty strong in Western Europe, Russia, China and across the North Pacific.

Rightly or wrongly, Skyteam has been branded as the weakest of the alliances because of some member airlines with less than sterling reputations, such as Alitalia, Aeroflot and Garuda, but this is more often a case of nitpicking and stereotyping. Certainly Aeroflot is a much different airline today than it was in the Soviet days (when it was, frankly, scary as hell.)

With regard to your proposed route for the Tokyo-based RTW, let me just mention that you could also squeeze in a visit with your LA and Portland people and still stay under the 26K mileage limit (which I forgot about) - see below - like this - NRT-MSP-SDF-ATL-LAX-PDX-SEA-AMS-SIN-DPS-TPE-NRT. However one feature of the 26,000 mile products is that they severely limit the number of stopovers and where they can occur, and in this case you'd have to limit your visits to "forced overnights" between flights at LAX or PDX (meaning under 24 hours, or else it becomes a stopover.)

Moving to the 29,000 mile IRTWSKY3 product from the IRTWSKY4 would raise the base fare by around $600, but give you another 3,000 miles to play with - for example a separate trip to LAX and/or PDX during your long USA sojurn - but would also eliminate the stopover restrictions.

You asked about Star or Oneworld versions of the same sort of itinerary. They'd look something like this.

Star (note business class not offered in their 26,000 mile product, so 29,000 miles is the minimum) - NRT-ORD-SDF-DEN-PDX-SFO-LAX-DEN-SDF-EWR-AMS-SIN-DPS-TPE-NRT. Base price for this would be $5587, around $300 more than Skyteam's 26,000 mile product but $300 less than Sky's 29,000 mile one.

Oneworld - this would be a 3-continent ticket without a mileage limit, base price $5417, so around $150 more than the Skyteam 26,000 mile RTW, $450 less than the Sky 29,000 mile ticket. NRT-ORD-SDF-ORD-LAX-DFW-SDF-PHL-AMS-DOH-DPS-HKG-TPE-NRT. With this ticket, you could add two segments within Europe/Middle East and one in Asia without changing the price.

So you can see the outcomes are pretty similar, but with different hubs for connections. In terms of flexibility, it seems to me that the slight premium for either the Skyteam or Star 29,000 mile tickets, or the negligible one for the Oneworld 3-continent ticket, would be in your interest, mainly for the stopover flexibility you have with the longer tickets compared to the very restrictive limits on the one you've priced. I'd also mention that any changes to the itinerary, except for simple date changes, requires the ticket to be re-issued with a fee of $125 (cheaper than most changes to conventional tickets) and a re-computation of taxes if applicable. (Different airport taxes might apply, for example.)

As for the omnibus table comparing the fares, the simple fact is that there are just too many products to price. People have tried to set up "scrapers" that access the GDSs, but these have very limited usefulness because in addition to RTWs, there are products like "circle Pacific," "circle Atlantic," and similar things that clutter the field.

In addition, the alliances themselves can't publish a table, because of various national (or EU) laws that require that airfares be published as "all in" prices - including taxes and fees. This is impossible with these multi-flight products because the permutation of possible itineraries, each with unique taxes and fees, jumps into the millions of possibilities.

Instead, just subscribe to Expert Flyer or KVS, and you can access the base fares on a country-by-country basis. The fees and taxes you have to estimate, or else use the alliance online booking/planning tools to get to the bottom line. And of course, lurk on the global alliance boards here on FT for all the anecdotal information you could ever ask for, and more.