I work in a non-Jewish office environment. I slip into one of many empty meeting rooms (semi-occluded) to say Mincha and Maariv, but feel hurried when I pray that way, also because I hear the business buzz around me (even with earplugs). 

Should I wait till I am home and pray there at leisure or do it at work earlier when the preferred time arrives but hurriedly?

At work, I sometimes feel I can't say the Shmone Eisre with enough devotion and take my time. If I wait till home, sometimes it would not possible to say Mincha before sunset to boot, another consideration.