Mainly shoot lower ISO and tripod mounted work.
I work the same way, and have owned a couple bodies since its introduction (as well as v1 & v2 of that model). It is still a fine camera, though there have been improvements to sensor tech since it hit the market (most notably with the A7r/D800e cameras). The 1Ds3 uses a Digic III processor whereas current Canon models use the Digic 5 processor chipset.
Where this model stands out is in its weather sealed mag-alloy body. I've worked long days/weeks in conditions varying from windy/dusty to misty/light rain without any degradation to the buttons, electronics or general performance.
I did have one incident where the camera fell from a 4-foot surface onto concrete, shattering the top LCD panel and pancaking the mirror box housing and hot shoe. I thought it was a lost cause but CPS fixed it without a hitch (2-day turnaround!). The internal circuitry is mounted on flexible panels which are (apparently) easily serviced by CPS and the mag-alloy body consists of three separate sections (exterior, chassis and mirror box) for serviceability.
If you have concerns about its capture quality, perhaps you can try it out for a few hours and rent a current model
(e.g., 1Dx, 5D3) for a comparison.