I bought this keyboard after having tried one in a shop and being impressed with the quality of the sounds. The Cool!RotorOrgan was a very important factor in choosing this keyboard, as it is superb and very usable. I use a 'proper' organ (Roland VK-7) for gigs but I was fed up with lugging it to rehearsals so I got the PSR-E413 for practice as it is very portable and about ten times lighter than the VK-7. I am still amazed at finding such a good rotor organ sound in what is a relatively cheap keyboard, as most keyboards at this price tend to have decent piano sounds but very poor Hammond organ type sounds.
The other sounds are excellent as well, particularly the piano, tenor sax and flute. It also has some other good organ sounds, including a jazz-style Hammond organ and a good Theatre Organ. There are two categories of voices, the ordinary voices (about 130 of them) and the XGLite voices, several hundred of them. This could be slightly confusing as there are more of each type of voice than it appears at first. Changing voices is dead easy, this can be done by typing in the number of the voice, using the + and - buttons or the scroll wheel. There are also buttons to change the category of voices (eg pianos, organs, brass etc), which are useful, as with about 500 voices, this allows you to quickly go to the right type of voice.
The built-in styles are good and allow playing complete songs using the left hand to generate automatic accompaniment, so this keyboard allows you to become a 'one-man band'. I also like the 'music database', which allows you to create auto accompaniment that sounds like real songs, and there are some very good ones there, particularly 'I Just Called To Say I Love You', 'Apache' and 'Lucille'. The styles and music database cover a wide range of genres, from pop to 60s to love songs, although rock and reggae seem to be under-represented here. I would also have liked some ska, punk and new wave music, but I shouldn't complain, as there are over 300 entries in the database and for me, that feature is really a distraction as I am unlikely to use it in a band - but it is a very enjoyable distraction. Another slight gripe about this is that you can't play the songs properly unless you know the chord progression for them - it would have been nice to put these in the manual, although it is easy to look them up on the internet through guitar tab websites. The auto accompaniment feature would be very useful for Open Mic nights or busking.
You can also record both melodies and accompaniment and there are six 'tracks', so essentially, you could record six different instruments. The tracks can be muted individually once recorded. There is a limit on how many songs you can record but if this became a problem then they can be transferred onto a PC. This recording feature is essentially a basic MIDI sequencer but again, used with a computer, more advanced things are possible.
The keyboard has a pitch bend wheel, which you don't get on cheaper keyboards and two knobs, which are useful and can be assigned to different parameters, such as reverb, chorus or song/style tempo. The keyboard is very easy to use right out of the box and the buttons are intuitive. For more advanced players, there is a vast array of different functions that can be changed. Admittedly, I found this particularly easy to use because my previous practice keyboard was also a Yamaha.
The keyboard also has MIDI capability and can be connected to a PC via a normal USB cable to transfer songs and other data, although I haven't tried that yet. There is a CD-ROM included with software for this, but again, I haven't had chance to try it yet.
I am very impressed with the manual, it is very comprehensive and these days, a paper manual is something of a rarity. The downside is that there is no mains adapter included, this seems to be the case with all Yamaha keyboards but it seems a bit mean to me. You can put batteries in it but I imagine they wouldn't last long and would add considerably to the weight of the instrument.
All in all, I would highly reccomend this keyboard and it ought to suit all but the most advanced players, who need specific sounds/functions or more keys. My previous Yamaha practice keyboard is ten years old and the difference between the two is amazing.