Sanden will put bit more load than ND.
1 - Good Cooling on Low RPM
2 - Easily Available
3 - Even if you have weak condensor or evaporator still cooling will be good.
1 - More load on engine.
2 - Needs alteration to fit, Means new pipe new braket more kharcha.
3 - The Original one is expensive (Only go for original)
ND - Pros
1 - Less load on engine.
2 - Designed keeping in mind the engine power
3 - no alterations required.
1 - New one is very expensive.
2 - Its hard to get cooling out of these oldies.
3 - Poor cooling on low rpm or idle if the whole system is not working upto perfect condition.
Now my suggestions will be.
1 - get yourself success compressor its a singapur brand and its cheaper than Sanden and they even in the advertisment say it puts less load on engine. and users also say it puts less load.
2 - Get yourself Multi Aisle condenso or they also call it multi flow. This will decrease load on engine and compressor also improve over all cooling by atleast 25%.
I had charade i was using ND compressor and Multi Aisle condensor and cooling was good enough