It is a matter of preference, and yes the different models do give you different results.
I personally prefer Tinseth (the default) since I brew all grain batches and Tinseth is generally considered more accurate for full batch boils.
Rager is popular with many partial boil and extract brewers. It tends to give much higher numbers in general.
There is no right or wrong answer...though I tend to prefer Tinseth as I think it also handles high amounts of hops in a more realistic way.
Cheers!
Brad
