You only need the platform for major expedition riding, eg where you have to carry several days worth of water.
The Tara is a fantastic piece of kit, light-weight, stiff, reliable and ideal for camping if you need 4 panniers. I have ridden on tacks and trails with one. You do need to take care about hitting stuff but you soon get your eye in.
You could probably get away with just rear panniers for 2 people camping.