Top of the morning to you sunster.

There is 1,524KB Flash Memory on the PSR 2100 so you're looking at a little over "1" floppy disk's worth of User Memory for Style storage, etc. A vast improvement over the PSR 740.

And the PSR 740's inbuilt Styles should play just fine on the PSR 2100. You might have to do some adjusting though.

The Vocal Harmony has also been improved on the PSR 2100 compared to the PSR 740.

It is worth the upgrade in my opinion. There are so many other improvements, not just in features but in the Sounds too.

Best regards,
Mike