I agree with tabithakitten.
I think that the standard can look higher on DWTS because they don't dance as much of the steps of the set dance as on SCD, but do a lot of posing and 'swirly' bits! The introduction and the finale in each performance can each be a long as the set dance which makes a routine much easier to perform - something Len has really been moaning about so far on this series of DWTS. I know the US dances are less prescribed than in Europe, but some of the dances are almost unrecognisable in comparison to SCD e.g. the VW. Plus the audience loves all the showy stuff and boo Len when he quite rightly says there wasn't enough actual dance steps, but even I can see what he is talking about.
On DWTS the celebs are taught routines that contain far less of the technical content of each dance and a lot more of what Len would call faffing about. The level of technique learned on SDC is higher than on DWTS, but the routines on DWTS are more pleasing to the public. I'd say Kelly would be on a par with Natalie if she was on SDC. Mya is a pro dancer as far as I'm concerned. Donny and Joanna are like Ricky and Ali.
Like Natalie Lowe, Mya has also said on camera that they will keep doing routines that please the public rather than Len - they both know the other judges like the showy stuff too.
DWTS has played about with the format and dances for the last couple of series and I like what happened on DWTS this series. Around the half way point in the series there are two weeks with a double elimination and in those weeks, the couple with the lowest score after the public vote goes home. The next two lowest scoring couples are in a dance off and the judges choose which couple to save. The twist is that when the double elimination weeks start, every couple left in the competition has to prepare a 30 second dance off dance of their choice, so they get those 30 seconds to do their best to impress the judges enough to save them. The dance off dances are not show dances and normal rules apply (i.e. no lifts). It is a great way of starting with a lot of couples and still keeping the series to a reasonable length of time. I'd love to see this done on SCD as it really adds to the excitement of the show, as does revealing in stages every week ('The Moment of Truth' bit), who is safe and who is in the bottom three and in still in jeopardy.
At the end of the day DWTS has to keep the audience happy to keep the show's network happy, to keep the advertisers happy!
BTW Dancers from DWTS have competed against SCD dancers in the "Champion of Champions" showdown as the Christmas Special in 2005. The final four couples from Series 3 of SCD - Colin & Erin, James & Camilla, Zoe & Ian & Darren & Lilia - with Evander Holyfield (& Karen Hardy), and Rachel Hunter (& Brendan Cole). Darren won, Rachel was fourth and Evander was last (he was dreadful!). Rachel and Evander were on the first series of DWTS and there were only 6 couples. Rachel was 4th and Evander was 5th.
It would be good to see finalists from both shows compete, but what rules would they follow? I'd say make it a two stage competition - dance one in the UK under SCD rules and one in the USA under DWTS rules!