The development environment is a joy to use, although unfamiliar to the uninitiated, but very powerful indeed. Some people do not like the image idea or the fact that they can't bring their tools with them, but I love it. Pharo lives on my USB stick and is ready and willing no matter what type of system I am on, or whose for that matter.
Whatever the pros and cons of the image based system may be the immediacy and transparency of it is really enjoyable. It's a shame that the idea has been pretty much abandoned by all but a small contingent of developers.
Unfortunately, my Smalltalk skills are weak, but it is a great language. About 8 years ago, I signed up as a Cincom Smalltalk VAR, spun up on it, but never had a customer want me to use it (except for Cincom itself: they paid me to rework some of the documentation).
Anyway, I just downloaded a Pharo + Seaside installer, and may play with it while visiting family next week.
Did this happen with the standard workspace as it was distributed? This typical smalltalk experience might be acceptable you. There is a chance though that your customers won't find it similarly enjoyable.