Is a latecomer to congregational prayer sinful? Or is arriving early recommended?

Whoever catches the congregational prayer is not sinful for being late, but he misses out on reward proportional to what he missed of the prayer. It is narrated in a tradition from one of the Companions of the Prophet, peace and blessings be upon him, that he said to his son when he missed the first takbir: "What you missed of it is better than one hundred camels, all black-eyed." The evidence has encouraged early arrival and hastening to the first row, and warned against delay, such as his saying, peace and blessings be upon him: "And none of you ceases to be in prayer as long as he is waiting for the prayer," and "A group of people will continue to lag behind from the first row until Allah holds them back." Al-Nawawi explains "Allah holds them back" to mean from His mercy, His immense favor, and elevation of status. Ibn Uthaymeen pointed out that some people delay joining the prayer until the Imam bows, which causes them to miss the opening takbir and the recitation of Al-Fatiha.