I find that I can only daven with kavana, if I daven fast. I find if I daven slow, my mind starts to wander, and I have less kavana, but if I daven fast with a sort of rythm, I can feel the kavana. the problem is that when I am in a minyan, this can mean that I finish the Amida ages before others, and I am embarassed. My mind says, that this is between me and Hashem, and anyway others still davening will not notice me, but it does embarass me. What can I answer to anyone who may comment, although no one usually does?

Shalom U'verachah, There is no halachic definition of how long prayer should last, if you find that you say all the words with the proper intention then you have fulfilled your olbigation regardless of how long it takes you. Each person prays at their own pace and so you should not look at others to see how long or short it takes them. Kol Tuv