Wisbar Advanced Desktop: it depends, it can be slow depending on what images are used in the customization & how many pages you use.
WAD is very customizable but it takes time. I prefer to combine it with WA3... (I'm using both now for my HTC Hero theme
)
Get WAD if you like to get your hands dirty & WIN.
MS3 is great IMHO, unlike WAD I'd buy this by default though. Its a MUST have app.