Ok, don't know if anyone here has the expertise to answer this question, but I'll give it a try.
I just had the battery in my 12-year-old car replaced. They recommended it because it was showing some acid leakage, which in turn was putting strain on the alternator. Ok, and it was the original battery, so I'm not complaining.
But now my car seems a bit sluggish. Particularly when I change gears (it's a manual), the acceleration is just a little slower than usual to respond. Someone else might not notice it, but because I've been driving it for so long I do.
Should I give it a little more time to "warm up" to the new battery? Or go back and get it checked out? I'm off on a road trip soon and don't want any surprises!