If the tzibur is about the start shemonah esray however Reuven isn't up to Shemonah Esray yet, and Reuven knows that if he speeds up his davening he will be able to start with the tzibur, is it better for him to speed up his davening, but not have the kavanah since he will be rushing through the words, or should he actually say the words and miss shemonah esray with the tzibur? Would the answer be the same for all three tefillot? I would like sources please
The Chazon Ish was once asked by someone who wanted to daven at sunrise (naitz) but that day was running a bit late. He asked if he should skip a few of the parts of Pesukai Dzimrah to make sure he can daven shemoneh esray with the Minyan. The Chazon Ish replied- the idea is to daven. A hidur is to daven with naitz. Skipping is not davening. I guess we can extrapolate- each person knows what focused davening he is capable of doing. If he needs to move at a speed that compromises his kavana, then he is not davening, so why worry about starting with the Tzibur.