S40 devices can't run "native" Symbian/S60 apps (which are or can be more powerful than just the Java apps S40 devices support).
And on S40 devices you can't also add new audio/video encoders/decoders (codecs) to supoort audio and video formats that weren't supported when the device was made.
S40 devices also have an operating system which not really geared for multitasking (running multiple apps at the same time, having background apps do stuff while the user's attention is on the foreground app).
On the high-end side, S40 phones do not quite match the high-end of S60 based devices from hardware features point of view, either.
Linear Mode
