ARE MATERIAL AND MONETARY COMFORTS AN IMPEDIMENT TO GROWTH IN SPIRITUALITY??

No.

No It's not.it depends on the individual how he/she handles his comforts and money.It can also act as a test for the person-whether he is tempted,fall in trap of greed and misuse his wealth or use it as a commodity to help himself spiritually.
To be successful in the latest part of his spiritual journey one must be content and without worries and be comfortable in his surroundings with money/comforts or not.
Money also may act a tool depending on the kind of spiritual journey you are on.
It's not the money or comforts ,it's the individual thinking which is the impediment

No, need to eat, sleep warm, take care of families, spend time with others who are spiritual to share and support and be supported.  
Money is energy too.

Two Taurus & 1 Scorpio answered so far.  I find that humorous.   Of course, we Taurean types like money - so we aren't going to throw the baby out with the bath water.