Just bought the Croma bag less vacuum cleaner(CRAV0025)1600W; honestly suction is marvelous its 25000pa which is best in this class, I was skeptical about the Croma brand but it was a very good product. Technically its above average but price wise its economical.
As being a technocrat and from similar field I would suggest the new buyers to see the suction simply by keeping the hand on the suction hose and then compare the good product, "higher the suction better the cleaning" as simple as it is.