upgrading to a newer version using aptitude

[H.S.]

Hello,

I have seen quite a few posts about upgrading an older version of Ubuntu 
to the newer version using the update-manager. I am wondering, what is 
the relationship between this application and aptitude? Aptitude is 
supposed to be more intelligent package manager than apt-get was. I have 
been using it for some months on Debian machines and it seems to be 
working quite nicely. I have already tried it on Edgy but only for usual 
updates. Anybody tried upgrading a Ubuntu version using aptitude?

->HS