I have tried all three and bought the Virtuoso's. They are a large step up from both the Veena and the De-capo i. Well worth the money on the upgrade.
Of the three, I found the Veena to be the least desireable. Very direct/ highs a little too bright for my liking. Possibly if you don't toe them in, the tweeter will not get you as much. Bass was not as deep/ controlled as I would have liked in a floor stander.
I found the De-capo i to be in the middle. Not as bright/ revealing as the Veena. Bass was as good or better than the Veena. Not as warm/ full as the Royal Virtuoso.
I found the Virtuoso to be warmer, fuller in sound. Better bass than either the Veena or the De-capo i. Excellent detail, yet not in your face. Tweeters have to be on the outside, and you have very little or no toe- in. Ends up being just on the warm side of neutral. Imaging is as good as I have heard from a speaker.
On a short thread, I would not hesitate getting the Virtuoso. Since most are now used, there is little difference in cost between the three. So the Virtuoso is a bargain.