Reon is vastly superior if that answers your question.
The Integra DTR 8.8 is the equiv. to the Onkyo TX-NR905. They share very similar features with a slight edge to the DTR 8.8. The DTR 8.8 has two component video
outputs as the Onkyo TX-NR905 only has one output. Each unit still features three component video inputs. The DTR 8.8 has an added feature for each of its zone outputs, each has a dedicated subwoofer output.
The retail price I have seen on the Onkyo TX-NR905 has been around $2000. B&H has it listed as $1995.00. The Suggested retail for the DTR-8.8 is set at $2400. Personally I don't like the look of the Integra, I wish they would put a drop down face plate on their units to give it a cleaner look like the Onkyos have been finished, as well as getting rid of that very stupid looking metalic grey volume knob. Either unit is a great choice and should perform very well.
The TX-SR875 has the Reon processing, but lacks the toroidal power supply, and likely overall power of the NR905 and the DTR-8.8, as well as the networking and USB facilities. It can go for as low as $1400, a member here is selling one in the classifieds for $1400 (he hasn't used it hardly at all and still has all accesseries to my knowledge).
At the moment there aren't any other receivers that feature the REON HQV processing that Onkyo/Integra has on their top model receivers and processors. Yamaha is now using Anchor Bay, which is a tad better than the Faroudja DCDi chip found in Denon and the lower to mid lines of Onkyo/Integra.
Good luck with your decision.