I'm thinking of buying a gps sometime soon. Have googled the two main brands available in SA, i.e. Garmin and TomTom, and browsed various forums to see what users had to say about the two brands and various models... which basically and generally boils down to: "I own/bought a garmin/tomtom and therefore garmin/tomtom is the best!"

Seriously "helpful" information

... doesn't help me make a choice though...
I have the following requirements:
1. Extensive maps of South Africa (other southern African countries not necessary). Mostly tarred roads, but small towns and dirt roads in South Africa also covered. (E.g. I'd like to know which turnoff to take to Soebatsfontein when travelling the dirt roads of Namaqualand).
2. Accurate navigation, with lane advise / junction help
3. Non-expensive maps updates
4. Easy updating of maps
5. Initial budget of no more than R2000 (maybe up to R2500)
6. Traffic updates and speed camera warnings are nice-to-haves, but not a necessity
7. Reliable signal / no/little loss of signal
8. Easy to program
9. Alternative routes easy to view/choose
10. Should be able to include specific "way-points" before reaching destination on a long road trip.
11. Estimated time to reach destination - nice to have, bordering on essential.
Am I asking too much?

I don't know much about these things
I'd like suggestions please - and also which models and map sets to avoid...