Will an upscaler(Dvdo Edge)work for me?

New to this forum and to HDTV in general. I hope this question hasn't already been asked and answered a thousand times here, so I'll try to keep it simple and brief. Here's my system:

Toshiba 40FT2U LCD 1080p/60 HZ monitor
Yamaha RX-V471 receiver
Sony BDP-S580 Blu-Ray/DVD player
Magnavox DVR from cable provider (Charter)

Everything is connected via HDMI cables.

Certainly not a high-end system, but I'm very pleased with the picture quality of the DVD and HiDef TV stations. The problem is I live in a semi-rural area and the cable provider only provides a small number of HD channels. The SD channels don't really look even as good as they did on my old CRT television.

Will the Dvdo Edge improve the video quality of these signals substantially with the equipment I have? Does it actually bring them close to the HD/1080p quality I'm getting now?

Is there other equipment that would do the same thing better/cheaper? I've heard of receivers that have built-in upscaling. Might I do better to return the receiver I have and put the money I'd spend on an upscaler towards one of those?

Thanks in advance for any and all responses!

what sort of results can I expect with one of these units?