Can you give some concrete examples? As a long-time DD who has recently been exposed to Ubuntu and UDS, I have found the differences in how things are done interesting. In many ways it seems much easier to get something tried/done in Ubuntu because you only have to persuade the roomful of people at a UDS session then you can pretty-much go ahead. Getting major changes done in Debian is a much slower and less well-defined process. This is of course a double-edge benefit :-)
I'd be interesting to hear of experiments in Ubuntu that went well and ones that went badly.