In the search for the lowest possible price at all costs, sometimes you end up further behind than you need to be. EPS doesn't require a credit card to join (unlike CPS I believe), customs clearance, at least for me, has never been a problem. EPS is very consistent in that I know if my pkg is in Miami before 4pm, it'll be on the flight to the DR the next day so I can reasonably figure out the arrival date in Sosua.
Not every company can please everyone all the time. In the threads I have read over the past year or so, it seems that someone has complained about each of the main freight companies at some point in time. EPS based on my recollection, seems to be a company that is mentioned less than the others but most do reasonably well at delivering the service they offer.
For some, service trumps cost, for others, getting the beer mug here as cheaply as possible so that they can afford to put beer in it when it arrives is more important. To each their own based on their own priorities and needs.
In the end, many of the problems or delays customers encounter are beyond the control of the individual forwarder. I'm sure they all use the same cargo flight each day, so if the plane doesn't fly, or customs in SD throws an tantrum you really can't blame the forwarder. In the end it probably comes down to convenience. Find a company close to where you live, offers email or web updates so you can track your package and pick them. If it works out, great. If not try another.