I have also used Buffer and Hootsuite and Dlvr.it seems to be the best, it doesn't lose connections with any of the social media platforms like Buffer and Hootsuite. It also connects to google business which is a major plus.
The only negative is there is no app - which is where Buffer shines.
Answer: I don't think so, I am sure there is others outside of buffer, hootsuite and Dlvr.it, those are the three I have used and I prefer Dlvr.it.
Answer: Because it can automate google business postings, something that I haven't figured out to do with buffer and buffer is terrible via google chrome and I have no issue with Dlvr.it
Answer: It's a legit company, I use it daily for my social media automation. IMO it's better than Buffer and Hootsuite.