1) A satellite antenna mounted on the roof of the truck's cabin.
2) A shell corrector (similar to the one on Smerch) on each tube that improves accuracy.
3) Some sort of a box underneath the launcher tubes that may be related to a remote control system.
The optical device for aiming may be different tooo, but I can't confirm until I sea close ups.
BTW, the newer 122mm Grad rockets have a range upto 40 km. That in itself is a great improvement.
Using the Ural truck makes sense for the following reasons:
1) Cost and ease of maintenance
2) Ease of transportation (the larger MAZ vehicle of the Smerch is less maneuvrable and usable in confined places)
3) Troops are already familiar with the system.
4) Some export customers may not afford to buy the larger MZKT based sytem.
5) There may not be enough capacity to produce enough MZKT trucks to equip every brigade with MZKT based MLRS systems as well as for Iskanders, BAL-E coastal defense sytems, SAM systems etc.
6) Ural based Tornado-G is more than enough for the needs of artillery units at brigade level. The larger MLRS sytems with replaceable pallets will be for specialized artllery brigades at higher levels.
Note that this is the Tornado-G, there are also the Tornado-U and -S models that are supposed to be introduced. These will obviously need the larger MZKT or BAZ trucks to carry the heavier Uragan and Smerch rockets in quickly replaceable pallets. Whether they will be used also to fire the 122mm Grad missile as well is another question.
Edit: Artillery responsiblity at the brigade level rarely extends beyond 20 km. Larger MLRS rockets (like Smerch) have a minimum range of something like 20 km. They are of little use at brigade level. The good old Ural based Grad (now Tornado-G) is a proven system that will satisfy their needs. I believe the Tornado-U and -S models will equip artllery brigades that support the usual tank/motorized rifle brigades from further away or to deliver strikes at longer ranges.