Don't know about ipad but I got microsampler on good price(ex-demo)...
I would recommend selling 505 get a used padkontrol and buy a microsampler but look for the new lower priced(350$)...
However MS has some serious flaws such us you can't sample&loop immediately (like kp3 does) and when you choose a sample for keyboard mode you have to use the dial knob(very sensitive&not precise...).
Keep in mind that in keyboard mode the pitching isn't hi-quality and cannot be compared with software or other more expensive hardware...
I personally bought it only for one reason :
the sampling modes are unique...!
PS.I had 505(and 606) and the only reason I sold it was the slow workflow...
PS2. If you always use a laptop I'll make I guide soon how to use the keyboard and the mousepad for controlling some of the ms parameters(midi related stuff)
PS3.can't wait for the 3.56-3.60 hack

word. i've been thinking about selling the 505. i like the autochop, but chopping manually is easy enough...

and how would the padkontrol play with a 404? i'm midi-illiterate, and so i'm a bit intimidated by the padkontrol, but i've heard theyre dope...if you're using one with a 404 is there any way to pitch shift? in others words, trigger and manipulate a pattern from the 404 with the kontrol?

It's not difficult to set it...once you set up one pad then all the others are the same story....yes they are dope...probably the best pads(for me at least)

pitch shift? like 505 pitch function?

You can trigger the sounds of 404 and use the roll with the xy pad which is super!
I was thinking the padkontrol for the microsampler mainly but you can use it for both

^ i mean like time-stretching bpm-wise. i'm sure you can't but i'm fantasizing