We have a PIM, which displays a product feed in JSON format. With Lengow we were able to import it very easily and then we connected it to a marketplace. Price and quantity updates are very frequent, this allows us to provide always updated data to customers. It is difficult to create promotions from the interface of Lengow, but once you learn you can do it easily.
SE Ranking is on a good track when it comes to rank tracking. It displays a graph of your average position over time which is helpful and it can also help you when it comes to identifying some basic SEO issues with your website. It boasts as an all-around SEO tool, which it definitely isn't because it lacks a link database to be your go-to tool for everything SEO. Its UI is not optimized for ease of use, thus offering sub-par user experience. It has two different interfaces for different SEO tools which, I hope, they can incorporate into one.
The support is great but they don't have 24/7 support. And time zones can also be an issue sometimes. On the other hand there are plenty of guides and videos around to get yourself started. I never really needed support for "big" issues. And the help I got was good enough.
Lengow turned out to be much cheaper, for our current needs it was enough. However ChannelAdvisor is a valid alternative more complete and with more tools available.
SE Ranking was our choice based on the suite of features it offered compared to competitors as well as the # of projects you could manage. From a cost perspective, we feel it provides the most value for your money. Other SEO tools did not offer the lead generation features that SE Ranking offered as part of their monthly plan.
The website "health" report has allowed us to fix things that Google might find strange or cause us to lose rankings, which has been very helpful.
It's given us more visibility into what exactly our SEO management company is doing and how they are performing, and if things are changing or not. It's very easy to see right from the dashboard.
Being able to see how our competitors stack up against us has helped us know where to improve, what to focus on, and how to be even better.