I don't work for a storage vendor and never have but have helped sell, install and manage Tegile, Tintri, Compellent and Nimble storage, thus, most of my work revolves around storage. Word to the wise, stay away from any newcomer all flash solution. The number of all flash solutions to tank in the last few years keeps growing. I would guess most of the ones that have been bought out have sold most likely out of necessity. The cost of entry into becoming an all flash vendor is too small which is why so many are trying.
IMO there are really two types of SAN vendors. Vendors that focus on hardware and those that focus on software. The hybrid (flash and spinning disk) vendors are usually focused on the software while the all flash arrays are typically about the hardware. Compellent, although not built with flash in mind is a software focused solution.
Every storage vendor has botched installations and issues so don't get caught up in that, the support that comes with a botched install is what is critical.
Tegile, is ok but wouldn't be my first choice...its another ZFS storage solution with too many options IMO. Their support needs maturation too. Compression is good but dedupe is overrated. Typical volume based SAN with NFS, iscsi and FC (most ZFS based solutions have all three). ZFS based solutions are nothing new and have a history. All inclusive pricing is pretty awesome. Upgrades are pricey.
Nimble Storage is solid, they have excellent support but they are pricey for what you get if you are looking at the hardware. Compression is good. It's pretty obvious Tegile is trying to beat Nimble on price whenever they can. Typical volume based SAN with iscsi only but heard FC and dedupe is coming if that matters. Also, has all inclusive pricing which is great. Upgrades are pricey.
Tintri is my favorite storage solution for fully virtualized environments (mainly Vmware but Hyper-v and KVM are supposed to be supported soon if not already) because you don't have or be a storage guy. NFS based storage which may not sound too great but it is simple, smart and keeps you out of trouble as there is no volume carving. Support is decent but pricey. Upgrades are horizontal so you are basically buying another unit when its time for more space which keeps it simple but expensive as they all are.
Compellent is a very good storage solution and probably the only one out of any you have looked at that is close to being Enterprise storage (for very large environments). They have a unique flash offering, forklift upgrades are not necessary (unless you have a very old compellent), very good upgrade options, and there support is considered by many to be one of the best in the business (even after Dell bought them). It's still volume based storage so you will need your storage admin hat still.
Most of the new storage vendors don't give you much of a break on any upgrades these days. Most make you buy a full shelf regardless of the necessity so make sure you ask how the upgrades work.
Hope this helps. I have worked with quite a few more but these seem to be the contenders in this posting.