If you just want the sound and style quality of a PSR 1500 and don't need any extra features then the answer is simple: buy the PSR 1500.

But if you have a PSR 740 you can add a lot with OMB. I know quite a few owners of these older keyboards who will stick with it forever now they have OMB.

And if you want the best of the best and don't mind spending some time experimenting and tweaking, then you can create a quality that is not for sale in the shops.

Jos