I was reading the kitaab 'Ixyaa Culumuddin' written by the great islamic philosopher Imam Ghazali (RA), The imam says that if one does not put his soul and mind in his salat, it may risk him or even may not be accepted. For example, starting the salat with the intention "Ah, lets get this over with" like it's a burden and not a opportunity to meet your lord, which is exactly what it is. And so he goes on that if one does start his salat with that intention and just reads surat-al faatixa and when reciting " Ih'dinaas siraatal mustaqeem" and just says it out of his tongue and not with his heart, his salah would risk of being accepted. I see the way this is going and i see the reason being is because why treat the salah as a burden and something just to tick-off on your book instead of taking time and while reciting the ayahs , actually hearing the flying thoughts in your mind, picturing the drama in yawmal-qiyama, picturing the un-imaginable fearful wrath of Allah "Ghayril Maqduubi Calayhim", picturing you infront of Allah live, whilst praying, like as if your seeing him. (Hadith of Jibriil (A.S) meeting the prophet in human form and asking him what is Al-Ihsan? in which he replied " It is worshiping Allah as if you see him, even though you do not".
So then in my opinion:
One man's Salah that he puts his tears, mind , body and soul into it, is more worth then 5 of the one who's salah is read like a fast-forwarded tape recorder. absolutely is blank in the mind etc....
You shouldn't treat the Salah as a do or die thing, look at the benefits of it, Allah is swift in punishment, that is the truth, but also that his Raxma is greater than his wrath, so if you look to the Salah as a meeting and a time where you can speak to your Lord what a great intention that is, the whole universe is based on intentions and Allah raises everyone up in yawmal-qiyama based on their intentions.
Wa Bilahi Tawfiq.