I'm not being a dick or an elitist. I'm simply trying to point out that firmware replacement won't get you the equivalent of a more expensive camera. The hardware additional features are things that really do matter when you're taking photos in challenging conditions:
- A pentaprism viewfinder is brighter and easier to focus with in low light than the pentamirrors used in low-end DSLRs
- Memory card failure happens - having images written to two cards simultaneously can save you
- Being able to instantly adjust two parameters without going through menus makes life far easier when when shooting things that move
- Top LCDs show you all the most important settings/stats immediately without the battery drain that having the colour display running would
- Additional cross-type autofocus sensors work better in low light and with servo/tracking autofocus (e.g. for sports and birds in flight)
Ultimately "prosumer" is just a label - you should always buy the cheapest body with the functionality - but that aside, it doesn't apply to the Canon Rebel/Kiss line. These are very much mass market consumer cameras, with the trade-offs clearly favouring size/weight/price reduction. This isn't inherently bad, as you get a camera capable of taking pretty decent pictures for a relatively low price. But telling yourself it's a "prosumer" camera just makes you look silly, and if you do need to shoot in more challenging situations, you'll really appreciate the additional functionality that you get with something like a 70D.