Year over year, our research shows a roughly 50-50 split between IT people who want single vendor suites and those who want multivendor, a.k.a. best of breed. This is consistent across verticals, company size, revenue and location.
In our most recent survey of 444 business technology professionals involved with LAN equipment, we asked a different question, trying to get a better handle on respondents' preference for standards or proprietary products and when they might use either (this is from a larger data set I am analyzing). The data shows that most respondents, 67%, think proprietary products are to be avoided if possible, and a large minority, 32%, think that some proprietary products are acceptable. Only 1% think proprietary products and features have better integration and interoperation features than standards-based products.
In our 2010 IT Pro: Data Center Networking Vendor Evaluation Survey[subscription required], (we are updating that survey even as I write), multipath Ethernet, which underpins Ethernet fabrics, was ranked 13th out of 15 must-have features. In that same survey, "Proprietary features in advance of standards" was 15th out of 15. That's bottom of the heap, just to be clear.
There is a disconnect between what our surveys show IT wants (standards-based products) and what vendors are delivering (proprietary products). What to choose is a big decision because we are talking about an investment of time, money and expertise to roll out an Ethernet fabric. What you buy today will set the direction of your network for the next several years--most likely several product cycles, at the very least. Companies, at least none that I have talked to, don't re-evaluate vendors and switch every three to five years unless there is a very compelling reason--like betting on the wrong technology, such as Token Ring or ATM. Companies tend to re-invest within a single vendor or product family. The total investment spans a long period due to factors such as inertia, the cost to switch, avoiding disruption or pressing dependencies on the status quo by other critical systems.
Standards-based products make swapping easier because you can take another product that supports the standards, configure it and, in theory, swap it with nary a hiccup. I know it's not that easy, but it's far, far easier than swapping proprietary stuff. You can swap a Cisco router with a Juniper router and it all just works because the entire stack is based on standards. But just because IT can swap gear doesn't mean that they actually do swap gear. At least, they don't swap gear on a whim, but there is a strong practical and psychological comfort knowing that they could and that they aren't getting locked in to a proprietary product.