This post will be a collection of thoughts and my own experiences when migrating from a physical C160 to a virtual C100V appliance. Other IronPort ESA P2V appliances may be similar so it’s worth reading on!
The short answer is, yes.
The long answer is that it will require a lot of work on your behalf.
The new Office 365 midsize business plan is very similar to the E3 plan (bar some advanced features which most users probably won’t need anyway) without the more expensive price tag attached to it; for UK users this is £9.80 per user per month as compared to £15 per user per month… if you have a lot of users the cost adds up very quickly.