I wanted to get a consensus on what peoples preferences are.

I recently purchased a calibrated tamper and have been using it for about 2 months now. With this latest batch of coffee I found it was bitter and not very dynamic. The crema was decent. Yesterday I went one setting finer on my grind and used the manual tamper. It was like I used a whole new bean. The espresso was very enjoyable.

This morning I went one more grind setting finer and uses the calibrated tamper. It was over extracted.

Im still tweeking my technique but I get more consistent coffee when I manually tamp. I'm boxing up the calibrated tamper.

Interesting observation. However, for myself, when I went to a leveling-calibrated tamper I compared my manual tamper to the new tamper using three different coffees for about one week. I judged only a slight, very slight difference in taste and a consistently better pour from the leveling-calibrated tamper...hence my change over about six months ago with no turning back. Even at the World Barista Championship last year some of the baristas were using PuqPresses...now that's cheating IMO.

When you change two variables at the same time, it's impossible to tell if the output variance is due to one, the other or both.

Tamping pressure has a very, very tiny effect on the shots, but distribution, grind setting and tamp level all play big roles.

After RDT, then grinding into a separate vessel, then going way beyond WDT by stirring with a cocktail whisk, then funneling into portafilter and stirring level with a dissecting needle...

I more or less don't tamp at all. A few settling vertical taps, (no side taps) down on the hockey puck I use as a tamping pad, screw my grooming tool down into the puck. If I have the depth set right, I don't need a tamp. Sometimes I do a proof tamp anyway and rarely find that I needed it.

-Peter

I would encourage you to use some sort of Distribution Tool and concentrate more on grind, dose, time and don't forget WDT!