This was discussed in detail on a thread sometime ago.
Its a bit of a coin toss. I prefer avplan. I think its better for IFR & multileg flight plans. I also think it treats loss of GPS signal better, which is possibly the main reason I stopped using Ozrunways which will give erroneous displays with marginal GPS reception. But for me, this occurred nearly exclusively in the low flight levels in remote-ish areas. B050 VFR may not suffer this so much.
OzRunways might be a bit more intuitive for "point & shoot" NOSAR VFR flights. But, for me AvPlan is a more robust, more sophisticated programme.
I would agree with the suggestion to download the free trial copis of both and see which you prefer.
I should add, that despite the additional cost, I still stick to Jeppview for IFR maps & plates.