I began my less than illustrious song-writing late-blooming career with a used Yamaha PSR-2000. (I still have it.) Then I tried Cass's Mini-Korg but thought the OS learning curve was too much for an old geezer for me to tackle... so I traded it in for a used Yamaha PSR-S910. Loved it but wanted better sounding styles. I still have it and plan to relocate it next summer for use when I'm visiting my daughter and her family. Finally, I bought one of Mason's Yamaha PSR-S970's and am enjoying it's many features and especially like the new, Super-articulated styles.
Learning it's VH and Vocal Effects capabilities has been challenging but I'm finally beginning to understand. I still have a long way to go... but considering the cost compared to Tyros and Genos, it is the best kept secret for song-writers.
My excuse for staying with Yamaha is simple. Most all of the PSR series machines are strikingly similar in layout and function. The learning curve is not very steep and that allows me to write and record my songs without much difficulty. I've recorded more than 1000 songs now (some not worth the ink wasted, LOL!) and have an equivalent number of unfinished lyrics. These days, I spend more time pouring over my catalogue for candidates to be re-recorded or completely re-written. Sometimes only a word or phrase, sometimes utilizing a different genre and sometimes, nothing works except the scrap heap.
Nobody told me this would be easy but I really do enjoy it and appreciate all the great performing artists here at the General Arranger Forum of "The Zone." Arrangers, no matter which brand are pretty darn special.