Well, im a W950 owner (but already sold 3 days ago)
which is the same firmware of P1i , M600

as for me , the phone is very slow , as in going in to folders and stuff
on the on off side , the loading to on the phone is zzzzz slow
and the phone needs to load (it will says "BUSY") when u trying to save something as in
example,

when receiving a file from using bluetooth , it will goes in to a BEAM FOLDER
and from the BEAM FOLDER , if u press save from there , it is EXTREMELY SLOW to save
the word "BUSY" appears till it is done

and if u were to press "SAVE" from the beam folder ,
once it is saved it means saved already in the INBOX MESSAGES

and from there INBOX , u only play the file to saved it to the folder in ur file manager

it is extremely .............. boring to me

especially if a few files , ur fren is trying to bluetooth to you
that will take even slower to save

BUT theres also another way which is faster
once the files already in ur beamfolder , u press VIEW the file and when viewing u have an option to SAVE the file
which is much faster , not much of a loading in this way

hope i did give some important comments about the same OS firmware phone lor

NO offense to other owners
Just sharing a thought