You clearly don't know photography & moreover SLR photography.

The advantage of SLR compared to your S3IS:
1) Accurate optical viewfinder - S3 doesn't. Whatever you see on your electronic viewfinder or LCD is actually a delayed liveview.
2) Image quality - The sensor size of a dSLR is much bigger than S3. Thus the ability to capture a wider range of colors & tones.
3) Burst mode - The slowest of the dSLR selling in the market today can do 3fps, S3 is 1.5fps/2.3fps (based on dpreview.com).
4) Hotshoe - The S3 don't have it thus can't mount an external flash. And thus can't shoot beyond 20ft in low light condition.
5) AF speed - The worst SLR can AF in less than 0.5 sec. While S3 usually takes 0.5-1 sec to lock on.
6) Shutter range - SLR is 30 - 1/4000 sec. While S3 is 15 - 1/3200 sec.
7) Instant response - SLR power up almost instantly (0.2 sec average), S3 around 1-2 sec.
8) Shutter lag - entry level SLR is 80-90ms. S3 , I don't know.
And more..........

Actually, based on your primary usage, since you don't take moving objects, frankly speaking, you don't need a dSLR. And if you don't enlarge your picture, at 4R, you perhaps can't tell the difference as well.

So how the hell you would understand why people pay 3 times the price of your D40X for a F2.8 zoom lens?

The Oly E330 has spot metering.
And its Live-View is on par with the prosumers.