I have the AVR-X4500H, not the 4800. At the time I bought it, I was considering the lower priced 3600 for similar reasons as yours.
As I was setting it up, I learned that the 4500's remote control has preset codes allowing me to set it to work with external devices such as a TV, Blu-Ray player, CD player, etc. If I remember correctly, the 3600 could not do that. I don't know if it matters to you, but I like that feature.
Otherwise, both models were similar, other than 20 watts/channel power.
I don't know if the same applies to today's 4800 and 3800 models.