First I'd like to congratulate Zoho for the job it has done so far in bringing together an impressive array of in-the-cloud capability. I'd like to think that I'm representative of the kind of user/advocate you envision for Business (multiple time CIO, consultant, SMB to large enterprise experience). My reason for writing is to suggest a near term focus for your efforts on the Business suite that comes to mind as I try to adopt the product into my efforts.
That focus in my opinion needs to be in the near-flawless operation and almost seamless integration in the key Business capabilities of Mail, Calendar, Contacts, Tasks & Documents. In my opinion these four are the hub of what Zoho Business is about, group activity & interaction. I find in my week or so of trying to judge the fitness & (hopefully) be able to adopt Zoho as the center of my group capability that some things don't work and typical integration is still missing. As such I run into annoying function that is there but not working (reporting each as I go). I also run into what I consider typical integration between these four and the general desktop that is not present yet and causes an unproductive level of action. If these four work well and are integrated well, all else at a sufficient or better level of capability for this suite to be a real winner. If it isn't than it stops me dead from being able to depend on it as my core for day to day.
Let me acknowledge I come from a MS Outlook, Exchange, Sharepoint perspective (not perfect in the least) as the high water mark in those four core capabilities (along with high cost mark). I find Zoho fairly competitive already and would be extremely cost/capability competitive if what I mention in focus allowed Zoho Business to mature rapidly. Some examples of integration missing: