855D uphill performance

So we have got a 855D here on test right now, its a second hand machine with about 2,000hrs on the clock.

Apart from at shows its the first time we have used one so not really sure what to expect or have anything to compare it with other than the Polaris 400cc quad.

The concept I totally get, for farm work its superb, but the two things I am so far unsure about are the uphill performance and the runaway scenario going downhill.

For sure its a belt drive so I must expect drive to be similar to a torque-converter, I am well aware of this, the question I am wondering is how much is acceptable, because from what i can see it needs to be revving flat out the get any appreciable speed to go up a hill.

Is there a standard specification of belt tension (like that of the belt variators on the old combine harvesters) that is set or checked by the operator or a technician?

Now, the overrun going down hill, this is a "feature" of the machine yes?....just need to hold back on the brakes?

thanks