I don't remember how Dell deals with SAN maintenance, I thought they included 1 SAN maintenance event per year with the purchase.  Check with your Dell rep on that.  As far as FLARE upgrades, as long as you have active maintenance on the array, through Dell or EMC, FLARE upgrades are no-cost.  Customers who purchased CX4 systems running FLARE28 or FLARE39 are entitled to load FLARE30 on those arrays.  There are some advantages to using Thin Provisioning with FLARE30 such as RAID10 pools, (FLARE29 only supports RAID5 or 6), grow and shrink Thin LUNs, and ability to create Thick LUNs in a Thin Pool.  Your Dell engineer is correct that Thin Pools do not perform the same as Thick LUNs in traditional RAID Groups.  If you need very predictable performance for your application, tradiitional LUNs are preferred.  Since you are not planning to use FAST/FASTCache today, there is no requirement to run FLARE30 yet.  And you don't have to use Thin LUNs or Pools.  You can always upgrade later and use LUN Migration to non-disruptively move existing data into Pools if you chose to.  In fact, in FLARE30, migrating a LUN from a RAID Group into a Thin LUN performs zero page reclaim to return free space inside the LUN to the pool.  If you are running vSphere 4.1 on the array, you will likely see performance benefits with FLARE30 since it includes support for VAAI.
Hi,  Engineer from DELL comes to set up our new CX4 Stroage Array.  Unfortunately, he says that DELL only supports FLARE 29 and not FLARE 30.  At the present moment, we are not using Flash Drive and thus no auto-Tiering.  Besides, that Engineer says that thin provisioning gives unpredictable performance (He suggests using Thin Provisioning in VMWare instead).   Is there any potential pitfall for not using FLARE 30 on the CX4 ?  Needless to say, they will charge us extra money this time next year by asking us to upgrade to FLARE 30.  Your advice is sought.
Potential pitfall for using FLARE 29 with a new CX4 Storage Array ?