Depends on what you want to do. Do you want to play with a live band with drums? Are you going to play out? Do you use multiple keyboards? Over the decades I have played with live bands and used a dedicated keyboard amp, as they have multiple inputs and are easy to control. But the ones I have used are large, heavy and loud to keep up with loud guitars. PA speakers can work, but usually don't have multiple inputs, and in some cases are more difficult to control (rear mounted volume, etc.) and in others may not be as "forgiving". These days, though, I play with a band that uses all in-ear monitoring, so I don't use an amp at all, just a very good DI box and monitor with in-ear headphones. Much less to carry around. If I use multiple keyboards, though, I have to bring a small mixer.