Just as it is in automobiles, the greatest improvement in bike performance is in the tires. That's a fact.

I prefer brifters, as I can shift while standing and they are quicker. The first time (many years ago) I rode behind a bike which had the new brifters, the performance and convenience advantages were obvious. I still run barcons on one of my bikes because they do have a slight advantage in weight and reliability. I don't bother with "modern" compacts, since riding behind them convinced me that triples are much better unless one has the youth and strength to turn a conventional 53-39 double. See, it's all personal. Do what you want.