We started five years ago by using Vtiger, an open source tool. It worked OK for a while but we now feel that it is outdated. We tried an upgrade a while ago but it broke our systems, so we stopped updating it--I do not know if it has gotten better. We feel that nowadays there are better alternatives out there. In a few months we will be replacing it with Salesforce and others as we see fit.
We use Jitbit and we are pretty happy with it. We “hacked” it a bit so that we can use it for internal processes like vacation requests etc. We were thinking of transitioning to a proper set-up like NetSuite, but for a smaller company this works quite well.
For a few months, the Sharepoint part of Office 365 was not very reliable but now it’s working OK. Before that we were running Seafile which is an open-source tool. We switched to Office 365 and the file sharing tool came with it. It is nice to centralize everything in one platform and you can share and assign permissions. It is a good enterprise solution.