Everything above is true and correct.
Here is some basic comparrisons between the two:
Dynamic / Mercury II
1. Has CH3/4 RF modulator
2. Has component video output
3. Has a feature that lets you backup your channel list, then recall them even after updating firmware.
4. Has 7 buttons on the front panel, so in case you loose your remote, you can still use the receiver (Ch+/Ch-/V+/V-/Menu/OK/Cancel/Power)
5. Has signal lock tone to help you align the dish if you use the receiver
6. Has a universal remote
7. Made in Korea (good quality)
8. Multiple timers
9. Full size
DBS3500
1. Has fast speed blind search
2. Does not have CH3/4 RF modulator
3. Does not have component video output
4. Has only 3 buttons (Ch+/Ch-/Power)
5. Does not use universal remote
6. Made in Taiwan
7. Compact size
You can see some screen shots of the Dynamic Here:
Fortec Dynamic