Are the alpha or beta releases more/less stable than the daily builds?

If you really don't know the difference between those two, I think you really shouldn't be using Ubuntu+1 after all. (quoting aking1012)

Daily builds are updated pretty live with changes in the main packages that are installed by default.

Alpha / Beta are snapshots of Ubuntu+1 in development. They are generally tested for issues in ISOs (but doesn't guarantee you anything, really). So you are better of using Alpha to install if you are hoping not to run into issues when installing.

Unless if you are really low in bandwidth and cannot afford to update after installing Alpha, you should just install Alpha. Then again, if you are low on bandwidth, updating Alpha would cost you more on bandwidth as well.

Just a closing pointer: If you run into issues with alpha / beta releases (which happens quite often), we can't help you much with the issues.

Beta releases and daily builds are all effectively just points along the road to release. I've not had a beta that I couldn't boot with nor a daily build - others have had issues with them.

If you install the beta and then apt-get upgrade you could be at the same point as the daily build - if nothing has changed since - you could be beyond the daily build point. It is more likely to be beyond the daily build point.

As it stands here with a completely updated 12.04 - everything is working - for me.

If you are at all worried about the stability of installing 12.04 then the answer has to be install 11.10.

Just to have said it: None is stable. These are development releases that are likely to break your system. Only download them for testing or contributing.

If you want to use Alpha after reading the above, might as well save yourself the updating time/bandwidth and download the daily build instead.