The SR-6005 is a really older generation Marantz receiver. It uses the previous generation HDAM audio stages, which have slow slew rates and, as a result, have a very warm and slow sound. The newer generation Marantz receivers are better.
The Anthem make excellent HT receivers, but the sound is going to be the complete opposite of what you hear now. The Anthem are extremely high resolution and will sound very exciting and dynamic with movies. Music is likely to sound significantly clearer, but on some systems the Anthem can come across just a bit bright. It really depends. You can give it a shot from Crutchfield and see how it sounds in your environment.
An amplifier could improve things, but you are still limited on the preamp section of the Marantz receiver.
A new Roku or network streamer is likely going to make very little difference in your equipment setup, so I wouldn't spend any money on that right now.
The Anthem make excellent HT receivers, but the sound is going to be the complete opposite of what you hear now. The Anthem are extremely high resolution and will sound very exciting and dynamic with movies. Music is likely to sound significantly clearer, but on some systems the Anthem can come across just a bit bright. It really depends. You can give it a shot from Crutchfield and see how it sounds in your environment.
An amplifier could improve things, but you are still limited on the preamp section of the Marantz receiver.
A new Roku or network streamer is likely going to make very little difference in your equipment setup, so I wouldn't spend any money on that right now.