I have just installed my first RAID array within the last 2 weeks, and I must say, that article seems to have one error:
There is a performance increase using RAID 1.
As usual, I benchmark every possible performance increase in my computer. Having just installed RAID 1, and RAID 0, here's my results:
RAID 1:
No increase in write speed.
Significant increase in read speed.
Major reduction in seek times.
RAID0:
Slight increase in write speed
Major increase in read speed
Slight increase in seek times
These are in comparison to a single drive.
The website might be assessing write speeds, which would mean it mirrors my results.
To answer the original question:
I think it may depend on your RAID chip itself. Most would support different sized disks (or just plain different manufacturer). However, for RAID 0 or RAID1, you'd lose the extra space on the bigger disk (or might have to partition it separately to make use of it, depending on whether your RAID chip would allow that).
JBOD would accept all disks, and use them all. However, this is not a true RAID (come to think of it, RAID 0 is not a RAID at all neither). Not sure about performance difference in this setting.
As for one SATA and the other not.... I got a feeling its going to be tricky. On motherboards, I doubt it can be done. May be possible on a RAID card which accepts both SATA and PATA.
Bear in mind as well, that chances are, you'd need to reinstall Windows to get it to boot up on RAID.
Hope that helps.