Avanti Blade vs Giant Rincon

My old bike (diamondback outlook ~'99 model) carked it, and I am looking for a new one.

The salesman at my friendly local bike shop suggested a Giant Rincon (2005 model AU$500 - list price $559). My friend who works at a bike store suggested an Avanti Blade (lists at $580), citing its frame as being really nice (same one as used on their $2000 bike apparently). He said Giant bike's use shoddy frames. The bloke at the bike store said Giants have better frames, but then again, he doesn't stock Avantis :P.

To complicate matters further, my dad is suggesting a Giant Rincon with the gears changed from the stock 42/11 hardest gear to run 52/11 as the hardest. The bike shop quoted me $150 to upgrade most of the gearing setup to accommodate this.

Anyway, I'm thinking I might be better off with the Blade, as rather than spending $150 on harder gears, I get 48/11 as the stock hardest gear. However I'm not all that sure, so I figured I'd ask you lot :P. The other downside to the Avanti is I would be stuck paying list price, so its $500 for the giant vs $580 for the avanti.

I use the bike for travelling to work (6km return, 3 times a week), school (4km return, 6 times a week), the computer store (12km return, once a fortnight), and the city (15km return, about once a week). I don't have a car, so it’s my means of transport. I do occasionally take the bike on to dirt and sand tracks (and I mean tracks, aussie wilderness is pretty wild), but that’s fairly rare, once or twice a year at most. Finally I ride on fairly nice gravel/dirt paths in the city once every few weeks.

Sorry, I'm rambling. Anyway, what bike do you recommend? I could stretch to the Avanti Blade Sport (AU$950 list price), but only if it was really worth it. I'm also open to other suggestions.

Avanti Blade - http://www.avanti.co.nz/bikes_detail.asp?id=137&t=6
Giant Rincon - http://www.giant-bicycle.com/au/030....=45&model=9760

Thanks (in advance :P) for your help!