I know people in the days of downtube shifters that had a shifting pattern taped to their stem since it was difficult to shift both the front and rear quickly and efficiently
I agree here
especially in the day of downtube, fiction shifters (my Dawes still has the old Simplex friction shifters, but they control an older Suntour or Shimano 5-speed changer); that's an adventure going from one front gear to the next! I never count on being able to shift the big gears on the fly, and I wouldn't recommend it to anyone else -- even inthe age of STI.
On the other hand... moving up and down the rear gear cluster is a BREEEEEEZE with a Shimano 105 etc (I mean, it was 25+ years between buying new bikes and this new shifting system makes riding a blast!)
I relegate playing with the front gearing to when I am on a good long down hill or flat and want to get some extra OOOMPH. When I see a hill coming, I move back to the small gear (for you triple folks, the 'granny' gear) well before I start to climb.
The key is: get comfortable with any system, get out, and have some fun!