First off, I'll say that I work for Tegile and as previously pointed out, several Tegile employees did come from Compellent after the Dell acquisition as did I.
Tegile
I'm biases on the reliability, so I won't speak to that one. I will say there are plenty of other Tegile customers and can answer that for you though, just ask your account team to set up a reference or two. However, you shouldn't find that Tegile pushes FC because of NFS reliability, in fact we often push VMware customers to at least try NFS because of the integration we have with vCenter/ESX. With NFS in a VMware environment we can see per VM throughput, iops and latency from our management interface or through our VMware Plug-In.
Tintri
You've already stated the items I would point out regarding cMLC/SATA, HDD rehydration and scaling. At least they did just announce support for Hyper-V and RHEV, so I can't ding them on being VMware only anymore.
Dell Compellent
Having sold, installed and supported over a hundred of these systems from 2007-2011, I'd tell you it is a good product and works well. Data Progression is the data movement engine across the tiers and raid levels, but the key to it's success of moving the 2MB pages is Data Instant Replay (snapshots). Without regular snapshots, data doesn't really move down the tiers with the default Storage Profiles. In Storage Center 6.5 it has been announced that the array will have the option to compress data that has progressed down to the lowest tier and hasn't been accessed. FC & iSCSI native only. CIFS/NFS via server appliance.
Pure Storage
If you have the budget for an all flash array, then I'd suggest you compare the performance and price/TB of a Tegile all flash configuration too, but you seem to have already ruled this out based on price. Otherwise, Pure is like Tintri and Nimble using cMLC SSD drives. FC & iSCSI only.
Nimble Storage
Nimble offers compression, but no deduplication. Just like Tintri, Nimble only offers cMLC and SATA drives. iSCSI only support.
In general, cMLC and SATA isn't a bad thing and I would agree that as long as you have support the failed drives will be replaced. As stated by another person, most storage systems that leverage SSD do have ways to minimize the writes and maximize the life, but the fact is that the SSD drives will generally degrade in performance long before they actually fail. cMLC SSD drives typically have 1/10th of the write endurance of their eMLC counterparts, meaning you can write petabytes of data to them instead of hundreds of terabytes. Regardless of support contracts, you have to ask yourself how often do I want to deal with replacing a drive and how frequently do I want a drive failure to be placing my data at risk while handling the rebuild.
Good luck filtering through all of the noise and making your storage decision. I hope you become a Tegile customer, but understand you have to make the choice that works best for you. If you have any other questions regarding Tegile or even Compellent, feel free to let me know.
-Aaron