I switched from Aksiums (2010, they weigh around 1900 grams without skewers) to Ksyrium Equipes (2005, slightly lighter, but I never verified the weight). I never noticed a difference in how the wheels felt or spun up, but someone else might. A bicycle mechanic friend related an anecdote regarding someone who once tested how sensitive riders were to added weight (in the form of lead weights in the seat tube) on a bike. In a nutshell, professional riders noticed an increase of a few ounces, but non-professionals did not notice until nearly a pound of lead was added.
The actual weight of a wheelset often differs from the published/claimed weight.
You don't mention how much you weigh, or how much/where you ride.
I'm around 200lbs (91kg) and I average 50 miles (80 km)/week. Some climbing, mostly flat terrain. I'm not racing, so my primary concern is solid wheels which are not high-maintenance and represent good value, last a long time, etc. I got tired of broken spokes on the rear wheel when I was riding Mavics, so I switched to these. I think I'd be better off losing some weight than paying big money for lighter wheels, but I might think differently if I was lighter and doing a lot of climbing.
My $0.02 would be to get wheels that fit the kind of riding you're doing. In my own case, the Mavic Ksyrium Equipes were a foolish choice, in hindsight. I got them off eBay for a good price, but I didn't find out they were 2005s until I got them, and after three broken spokes ($30 each to fix at my LBS) in 3,000 miles, I decided to get something that required less maintenance. Mavic wheels use proprietary spokes, which many LBS do not keep in stock. There is enough information out there on the 'Net to make it clear that Mavic wheels are not made for 90kg+ riders, and I should have done my homework more carefully. I would encourage you to do yours.