From a hashkofic perspective:
How choshuv SHOULD davening be to a yid?
Compare;
To arrive late: would you arrive late if you had a plane, train, or bus to catch? would you arrive late to a family simcha? (assuming it is a close-nit family of course)
To leave early: would you leave your family chassuna early?
A bizoyan towards the tzibbur: How would your family feel if you left the chassuna early? how would your spouse/kids feel if you came home, ate supper, and left in a hurried manner?
we have to remember to view davening not as an obligation or a ‘service’ but a privilage of the highest order! For us humans to actually meet and converse with the King of Kings, and tell Him what is on your mind, request our needs, even to offer praise to Him, is an absolutely incredible opportunity and honor if you think about it. You would salvage the moments in tefilla, and bask in the delight by davening slowly and not quickly.