I've been with 3D Cart for a few years now, and initially I was very pleased with the setup, the options and the easy to navigate administrative area. What they suggest that they offer does not always seem to be the case, however. I selected 3D Cart for 2 main reasons: 1) their compatibility with QuickBooks and 2) their proximity to my physical location (support local business!). After the very time consuming setup process I quickly realized that their Quick Books integration was nothing like I hoped it would be. The technical support that they provide is very limited- many times calls were unanswered and the tickets I entered were consistently escalated with absolutely NO follow up. I became a pest that was extremely upset after months went by of "escalation" and the end result is I received a 1 month credit to my bill and no resolution to the problem. As a matter of fact, this issue was a year ago and I expected that at one point SOMEONE would follow up with me but it never happened. I find that nearly none of their social media tools work, and most of their marketing shopping cart exports and "coupons" don't work. Without exception every single one of their shopping engine coupons has said "expired" and always has said "expired" when I attempted to use. The FaceBook shopping cart export does not work either. I have not entered tickets on these items because of my frustration with their lack of communication and follow up. The tiers of their cart offerings and monthly costs seem to make it not very cost effective as it relates to smaller company stores with approx. 2000 products. Clearly, I cannot bump the account down to 1000 products for the costs savings but rather I need to select 5000 products. It would be nice to have a level in the middle. All in all my store functions OK, but I limp through the year with little revenue and struggle with back end balancing due to the lack of downloads and syncing with my finance programs. I am a online store owner that works full time in addition to running the store so I struggle with having the time to troubleshoot technical problems with 3DCart. 3DCart has tons of potential, but may need to "beef up" on its customer support and technical support. For an online store owner with high level self troubleshooting skills it may be a good match.

We have two carts with 3dCart; one for a little over a year (still running 2.2 due to a migration glitch that cost us 5 days of downtime!), and a new cart in 3.0.
(1) Service...it can be frustrating, and rarely timely. They eventually reply by email, which is good, but don't include your original question. Their answers are as concise as possible (too concise), so more often than not I'll need to spend time going back to correlate the answer to the question. Takes forever to resolve even the simplest issues. (2) They charge you a fee every time you upgrade or downgrade and account for seasonal fluctuations. (3) Limited functions with downloadable products. (4) Setting up customer shipping options for different customer groups is far more time-consuming than it should be.
Both of our carts are seriously customized in that we host our own buy pages and just use 3dCart's checkout pages. With the FTP access we can go in and make fundamental layout changes that can't be made in their otherwise quite extensive content management system. All in all, we're happy with the carts, but frankly, the inconsistent service often has us wondering about optional sources, or possibly hosting our own cart. It's all about service...timely, professional, friendly and thorough...and they are weak on all of these points. Too bad, as otherwise they would be an all-star resource.