Hi ghn4ever, progressive hammer and graded action are both the same thing. Different manufacturers call them different thing for marketing purposes. Also, they like to confuse people...
This topic has been discussed in length a few times. If you do a search, you'll find some very useful info. But a quick summary:
1. CP300 will be your best bet. Yamaha has the most realistic touch compared to all others. It's a huge improvement from the predecessor P250 which was already a hit. And of course, the build-in speakers is very helpful. The only problem is the sound - Yamaha piano sounds are OK but they need to improve on their sampling technique. Higher registers are always a tad too bright. I'm not sure if it has arrived in Singapore.
2. RD700SX is one of the best (if not the best) stage piano for live performance. It's design is extremely ergonomic for quick access to what you need on the fly. Roland has thought of almost everything a live performer need; apparently they've put a lot of thought into it. Problem is, of course, no build-in speakers. For home use, you'll need to get extra speakers. But it is also a great keyboard to play with. Action not bad either. The Roland piano sound is one of the best; same goes for their orchestral sounds (ie strings etc).
3. FP-5 has build-in speakers. The action is somewhat slightly lighter to my liking. The FP series is one of those few unusual keyboards with the build-in speakers facing both towards the player (upwards) and the audience (forwards - located at the back of the keyboard). That way, both the player and the audience can hear what is played clearly. The speakers are not as good as the Yamaha. I've not tried the CP300, but the P250 speakers reverberate within the body of the unit. This adds to the "feel" of playing a real instrument - a very pleasant experience. Roland lacks that.
4. CLP series - well, if you are not going to move your keyboard around, you can get it. Don't be fooled by the number of sample/note (what Yamaha calls level of dynamic sampling). It is supposed to add to realism of the sound. But that is only as good as the sampling of the raw waveform and how long they sampe each note. I've not tried to CLP280 to comment, but most of my experience with Yamaha sound is that they sample the notes too short and then loop them. What is irritating is I can almost always hear the looping points of each note (in the P250, in the S90, in the MOTIF, in almost every piano sound I've heard). This may be different for the CLP280 - I don't know. You MUST try out the sound for yourself.
5. Roland HP series - simply one of the best upright digital pianos! I've tried both the HP-105 and the ultimate (KR grands). The touch is amazing - Roland came up with key escapement (on a real piano, when you press the keys down, you'll find there's a slight catch of which you can press it further down a notch - Roland made it the same way). Not all HP series come with escapement - only the higher series. If you have the money and portability is not an issue, the KR series will be
THE digital piano to get.
This a quick review of the ones you mentioned. Don't forget to check out Korg's SP series, which to my opinion does not match up to Yamaha and Roland in terms of touch and sound. But again, sound and touch is a very subjective thing, although my opinoins tend to agree with classical and acoustic piano players.
Hi every one,
There is only one used piece of SP500 left in Luther Music Show Room. Although it costs only 1280 bucks, there are a lot of scratches on it. 
Didn't realise the p250 has so many more buttons than my p200.. heh.