"A quick google has shown it has a much smaller crew than an E3 so what would be its shortfall in ops NATO is likely to conduct?"
The Turkish AEW is not officially part of the NAEW Force and therefore NATO cannot task it - it is a national asset (The FAF E-3F often "joins" the NATO Force, but this is on a voluntary basis). The experience that the E-3 has of working with smaller assets is when on ops with the USN Hawkeye. The Hawkeye does not have the same capacity to carry out the "AWACS" task as the E-3 - nor does it have the legs.
The "problem" with the E-3 is that it can carry out many C3 roles - unfortunately CAOCs have the habit of trying to task all of them simultaneously, in which case the E-3 rapidly runs out of consoles and radios. Often the smaller platform will be given a supplementary role thereby allowing the E-3 to get on with its business. This is not decrying the crews of the smaller platforms, which are often in AEW roles as supposed to AWACS roles but a practical way of employing them in support. (Yes, the RAF procured a very capable AEW platform that adds much more in the way of C3 support).
For the future? As the individual E-3 fleets enjoy their mid-life update away from the block 30-35 model, they diverge away from a commonality of capability. The difficulty in future ops may be the integration of the many E-3s of a different standard in a common operation.