First decide what is important to you, performance, capacity, scalability, maintenance costs, reliability, quality of suppliers etc over the required life of the storage (eg what extra workloads would be added over the next 5yrs).
You will get sales people all over you saying they have a solution that will meet your needs, but there are so many options that to get the one that works best for you requires competitive analysis based on your criteria.
When a company says we have a feature it doesn’t mean they do it well, so watch those feature matrices and go beyond the check box when validating against your requirement - if it’s a feature no one uses due to issues, that won’t work for you).
Choice of supplier of whatever solution you choose is critical (to avoid wrong spec / poor implementation).
Speak to each manufacturers representatives in addition to suppliers initially (via twitter, trade shows as well as your local manufacturer rep).
Ignore anyone saying a competitive product has a weakness, trying to instill in you fear, uncertainty & doubt to make you buy their product. Address any of these with the other manufacturers reps in addition to customer references & other sources, keeping your own requirements in mind.
