The main differences between them were more likely comparing a normal Astro decoder with Beyond:

1) 500S
250 MHz IBM PowerPC Processor (350 Mips)
SPDI/F interface for digital bit stream out (AC-3 / DTS)
MPEG2 Hardware decoding
Video Standard PAL and NTSC
Video Formats 4:3/16:9
No PVR

2) 800HD PVR
Main features are a 300 MHz processor
Dreambox DM800 supports Linux TV API have a look to High Definition TV on your Dreambox - 1080p
10/100MBit compatible Ethernet Interface
DVI connector
brilliant OLED display
SATA for use either as internal HDD 2.5 or eSATA

3) Openbox are another choices for Satellite TV Receiver HD series with the same functionality with a cheaper budget. Supports PVR, HD and external HDD.

Yes, you still could watch HD with an ordinary dish.

Great info. Thanks