I bought my first Oregon in 2010 for hiking (450T), when I was travelling to a country without adequate mapping, I've used it and its recent usurper (the 650) extensively since through all manner of countries and areas for hiking, cycling and driving (>20 countries). While I love it to bits, I've never splashed out for the 1:50000 although I can see how they would be beneficial, the job is done to a greater or lesser extent with any map.
Acknowledging everyone will have their own preferences, when I tried it I was actually shocked how poorly the 1:25000 served in comparison with the paper version, which made me consider how I was using the various mapping components.
The Oregon I generally use with the map in track up mode, switching to North up if I need to plan. I want it to tell me which way I need to chose, where I am in relation to other stuff (eg how far to go, climb or descent) and where I've been. I rarely plan a walk or ride on it, the times when I end up doing planning on it tend to be very limited and the outcome is rarely as successful as something planned in advance.
The paper map, by contrast is excellent at showing the lie of the land; what else is about, how to route and its use is intuitive. When combined with a satnav which takes all the "but where are we REALLY?" out of the equation, they are brilliant at adding to the enjoyment of the day, the 1:25k far more so than the 1:50k. But, I found that the 25k on screen provided none of that capability. YMMV, but do try first, if you can.