First, it takes a while even for experienced stick drivers to adapt to a new car and achieve smooth gear changes. I would be surprised if there was no hiccup during your test drive. If there isn't any, it means you're a natural
. But I don't think that learning to drive stick during a test drive is fair to the car.
Second, I've driven stick all my life, and never considered anything else until I drove an M3 with DCT (in manual mode). IMO, it's really the best of both worlds. Personally, I really don't think that activating the clutch or going through gearbox gates is an essential part of the driving experience. I've never had as much fun on four wheels as I've had in a shifter kart. Believe me, when you drive a shifter kart on a track you never tell yourself "I wish I had a clutch pedal and a non-sequential gearbox". DCT is even better than a shifter kart's gearbox because it doesn't require you to lift before shifting. Again, all this applies to DCT in manual mode--auto mode is not that much fun.
If you've never driven stick, my advice would be to get a car with DCT. The adaptation period will be much shorter. You will have fun right away. And let's face it, DCT is the future of manual transmissions. Resistance is futile