My opinion is that the short term pain of learning the MDX/Cube environment will far outweigh the countless number of new SQL queries/modifications you'll be writing when the business expands and/or requests new variations of the existing data - not to mention another string to your bow in terms of experience.
I look after a cube as part of my everyday duties, and it covers 99% of my reporting needs - the remaining 1% I cover with stored procedures, and generally that's when I have to built a report with a large number of parameters and parameter variations.