Hi Suzy,
Yes it's absolutely worth the extra money.
I think the
CLP-340 has the best value for the money (maybe apart from the CLP-370 with it's White Wooden Keys) in the CLP-3xx range if you want a piano close to a real accoustic AND still affordable.
1. The GH3 action with 'Synthetic Ivory Keytops' gives a pleasant familiar feel with regard to a real accoustic piano.
2. You have 4 soundsamples per note in stead of 3 for the
CLP-330 . (Means slightly richer sound).
3. Much better amplification and speakers: 40 Watt x2 (in stead of 20 Watt x2), speakers 16 cm x2 + extra 5 cm x2 for the CLP-340. So this means the bigger speakers are only used for the middle and bass tones. Result much 'bigger' realistic sound, clear high notes and especially more realistic lower tones, very important for a piano sound.
4. 14 x 2 instrument voices in stead of 14. (Nice, but not very important for piano playing)
5. Key-Off Samples and Stereo Sustain Samples ! (Makes the sound much more realistic).
Info about:
"Key-off Samples" and
"Stereo sustain-samples" (realistic open-string effect with the sustain pedal).