Is it fair to say overall but vt20 would be better as it is v top series compared to st30 s series?
Which all sources does this 50 hz issue become a problem in? only tata sky or sd dvd also ?
Checkout my comparison thread. In short, The TVs are more identical than different except what follows.
VT20 has more colour accuracy (mostly due to extra caliberation controls), excellent bluray 24Hz Playback (unusable in the ST30), very slightly better blacks, better details (which is also revealing in not so good SD/HD material)
ST30 has better 50Hz motion (a bit too smooth according to reviews), Has 2D->3D conversion, Comes with only 1 glass even at 90k (so the price is ~1L)
Other non-PQ differences include 'thinner' bezel in the ST30 which IMO is irrelevent after some amount of thickness but is a good to have.
ST30 literally has nothing worth 25k over the VT. You can get a good 32" LCD for the price difference and use it in your bedroom.
These two TVs have the below compared to samsung Plasmas.
1. Less richer and more true to content colours (I prefer samsung)
2. Completely different league in blacks
3. Worse motion
4. Not so accurate skin colours
5. Much better background seperation (depth), accurate scene highlights (spot lights, street lights, glittering objects, candles, shadow details, dark scenes with blue face highlights) [Both these are related so putting it as same point]
6. Very much controlled reflections comparable to LEDs.
7. Less sharp and more natural flowing pictures
8. Less retention
9. Poorer upscaling/SD overall
10. Much more cleaner picture with less noise
This is after to and fro viewing from the TVs at my living room (VT20) and bedroom (Samsung B450).
What to select between D550 and VT20 is a wrong question to ask since they did not compete with each other all through their lifetime. You might think that the VT20 will triumph D550 in all departments since it was in a different price level but it is not.
What to select between the D550 and ST30 is a correct question and the answer is D550 since they are sold for the same price internationally. At the same price though ST30 has an edge. In india, It is D550 until you want to spend on the characteristics in which ST30 is strong.
Also, certain improvements done by samsung to make their LCD acceptable are incorporated in the plasmas and they look multiple times better in the plasmas. Panasonic however has been concentrating in improving the panel all this time mainly the blacks and produces non-alterated, non-motion compensated, true to signal pictures. It is not always better than altered picture of the samsung as you can see in the above listing.
Hope you have all the details required to make the decision.