You get 5 with the tech pack, regardless of whether you have connect or not. I didn't think you get any with the standard SD nav, but not sure.
Connect features I use most: Google Earth imagery, live traffic updates, text message dictation, parking information, online destinations (ie, google search for destinations - Audi's database is far from complete!), send to car, wifi hotspot. Would I miss it? Yes!
I'm on the pre-paid 3 month Three SIMs at the moment, you can get longer ones but just never been in a position to shell out £70 at once yet. It's about £20 for 3 months of data. For the usage I have (I have google earth images turned on) I use ~300MB a month. Coverage is really good with Three. I originally had a T-mobile/EE SIM in there but coverage was awful so I got rid of that one.