I've used Baja Sandblasting twice--first in 2010 to sandblast the entire exterior CMU block of my mid-century home and again yesterday for two walkways, a low wall and to touch up the exterior after I made a very bad decision to have some areas re-pointed--the mortar didn't match and looked terrible. They also do great sandblasting of wood--they touched up some stains from leaks before the roof was repaired under the eaves and also did a fantastic job.
Ramon and Jose Luis are great to work with--we determined the price up front for the scope of work, time required and prep. Their crew were polite, careful with plants and outdoor furniture and they were meticulous with protecting windows/doors.
The quality of their work was outstanding and I am very, very happy--I have used them twice over a six year period and they are the only sandblasting company I would use.