'04 Z2

I noticed this morning that my Blazer is real sluggish shifting into OD. It took about 3 seconds from start to finish at more than 50 mph with little throttle. I've had a Safari for 10 years that still shifts much faster, typically at 40- 45 mph. Is this going to toast my clutch or is it normal? I've spoken to trans. mechs. in the past & all have told me GM OD's are good for business. I'm going to talk to the dealer since only a week old but I expect to be told it's normal. It just don't seem right. Any thoughts ?