It's easy to use with good customer support available 24/7 which makes things easier than ever! I can't think of anything that we dislike so far as it has been very helpful thus making our life much more enjoyable especially when you're working through tight deadlines or during busy periods (Christmas).
The only thing i do not like about this system would be if there was an option where someone could easily add new products rather then having us search everytime by hand but they already have plans set up around adding such feature. We've found no problems at all using espservices from start till finish process including invoicing clients etcetera.