Hello all.

First time posting to this board, and also a newbie when it comes to all the technical aspects of home audio, so please bear with me.
I purchased the M60's and VP150 a month or so ago, and have been very pleased with the performance. But, I'm looking for some advice on receivers. I have a Sony STR-DE598 with the following specs (power is towards the bottom):

Product Specifications
Convenience

* AM/FM Memory Presets : 20 FM - 10 AM

Power

* Power Consumption (in Operation) : 220W
* Power Consumption (in Standby) : 0.2W
* Power Requirements : AC120V, 60 Hz

Weights and Measurements

* Dimensions (Approx.) : 16 15/16 x 6 1/4 x 12 1/4" (430 x 157.5 x 310mm)
* Weight (Approx.) : 17 lbs 10 oz (8Kg)

Audio Features

* Digital Cinema Sound™ Technology : Yes
* Dolby® Digital Decoding : Yes
* Dolby® Digital EX Decoding : Yes
* Dolby® Pro Logic® Decoding : Yes
* Dolby® Pro Logic® II Decoding : Yes
* Dolby® Pro Logic® IIX Decoding : Yes
* dts® 96/24 Decoding : Yes
* dts® Decoding : Yes
* dts® NEO:6 Decoding : Yes
* dts®-ES Decoding : Yes

Inputs and Outputs

* AC Outlet : 1 Switched
* Antenna Terminal (AM Loop) : 1 (Rear)
* Antenna Terminal (FM 75 Ohm) : 1 (Rear)
* Coaxial Audio Digital Input(s) : 2 (Rear)
* Component Video (Y/Pb/Pr) Input(s) : 2 (Rear)
* Component Video (Y/Pb/Pr) Output(s) : 1 (Rear)
* Composite Video Input(s) : 4 (1 Front/3 Rear)
* Composite Video Output(s) : 2 (Rear)
* Headphone Output(s) : 1 (Front)
* Multi-Channel Input(s) : 1 (Rear)
* Optical Audio Input(s) : 2 (Rear)
* RCA Audio Input(s) : 6 (1 Front/5 Rear)
* RCA Audio Output(s) : 2 (Rear)
* Subwoofer Output(s) : 1 (Rear)

Speaker

* Center Speaker Terminal : Yes
* Front Speaker Terminal : Yes (A & B)
* Speaker Terminal Type : Spring Clips (A & B)
* Surround Back Speakers : Yes
* Surround Speaker Terminal : Yes

Hardware

* Remote Control : Yes

Audio

* Channel Power Rating : 7.1 Channel Power Rating: 90W x 7 Amp Power (8 ohms, 20Hz-20kHz, THD 0.09%)
* Impedance : 8 Ohms
* Sound Fields : Cinema - 4; Music - 3; Auto Format Decoding - 6
* Tuner Type : Auto Tuning, Direct Tuning, Station Name

My question is.......the receiver seems to have sufficient power to drive the M60's and VP150, so, if I were to upgrade the receiver significantly, can I expect the "sound quality" to improve significantly? I know the Sony is pretty much a budget receiver in terms of cost, but will I gain a lot in sound quality by spending bigger dollars on a new receiver, or will I simply be paying more for the newer "bells and whistles"??

Thanks


Sony Grand Wega
Sony AVR
Sony DVD
Technics CD
M60's
VP150
Nuance SAT 1's
Sound Dynamics THS-10 sub