There are few ups and downs at the moment since it's in alpha stage but in their own words...
"...judging by its early “alpha” version. It has the fastest boot-time we’ve seen on an HDD-based PC, shows snappy performance between applications..."
Although not entirely sure if the adaptation of the Kernel 3.0 RC+ has anything to do with it but it seems that the removal of GDM and replacing it with LightDM has done the trick. In any operating system, one of the early-loaded GUI services is the log-in manager, and since...
GDM has been criticized by many developers saying that it has about 50,000 pieces of codes while LightDM only has 5000, that's at least 10x lesser amount of software code thus it should have helped.
Anyhow in their test PC (Intel Core 2 Duo E8400 at 3.00 GHz and a usual hard disk, not a SSD drive, other hardware unknown) the Ubuntu 11.10 alpha was able to boot up (from the moment of switch on to log-in screen) within just 12 seconds!.
Thanks to Google Chrome type operating systems, there is now a "standard" that says any OS that has about 10 or lower seconds of boot up times is considered as an operating system with an instant boot, so in that sense, Ubuntu 11.10 is just 2 seconds behind and most importantly it has been able to achieve that not using a SSD drive (which is significantly faster) but by using a SATA HDD!.
Another key improvement is the Ubuntu Software Center since Ubuntu decided to remove Synaptic from the official CD/DVD (but still available through the official repositories), starting with the 11.10 version.
It's about time that they started to pay some serious attention to improving the USC, because from the beginning USC requires a lot of system resources (CPU actually, although RAM usage is not that high, pretty much closer to Synaptic according to my experience anyway) and the new improved USC in the 11.10 Alpha 2 seems to be quite responsive and fast than the one in the 11.04.
Anyhow it's really interesting what this means at the end because as any developer knows, since Ubuntu has no interest in targeting the "hacker" and rely on the "actual PC users", which I think will help them immensely in the future because it's this change of "attitude" (for good or bad) that has put them up there at the top.
If I remember correctly it was actually Ubuntu who was one of the first GNU/Linux (is it really?) distributions to speed up the boot up times where in the past GNU/Linux was painfully slower as well.
Anyhow, this should send some "alarms" across other distributions (or may be not) + we also have a little Gnome OS thingie going on at the moment, so it should be really interesting whether the other distributions have the ability to compete against this "Ubuntu trend".
Because a trend is a far more powerful tool which, if properly used can easily let you pass through the popular "players" easily, which can be seen a bit too much to dream about right now (oh I didn't made up that statement all by me own, saw something similar somewhere recently :D). But the rest assured, whether you love or hate Ubuntu, interesting times ahead, it seems.