SandyF wrote:
Hello Rick, Kendall, other old-time readers who may remember me! I haven't taken many photos in the past 2 years or so, and trips anywhere have been limited pretty much around our home state of Virginia since Covid appeared. My husband and my last trip with any photos of note was to Scotland in April 2019; many DPMerrill photos are visible on my flickr stream which you can find under Sandy Fleischmann. I've just downloaded the lastest SPP6.8.2 and processed a couple Shenandoah Valley VA area photos. One is linked (I hope) at the end of this post. My newest cameras are still the DP2Merrill and DP3Merrill (along with DP1M my go-to cameras). I'm tempted indeed by the SPQuattro since I could use my various Sigma lenses with it. The extra pixels of the Quattro would be welcome too. I note again how DETAILED and wickedly sharp the Sigma landscape photos are; details of trees, rocks, sticks, rushes and reeds... Landscapes and flower shots are still my thing. Suggestions re new gear?
Best regards, Sandy

Hello Sandy. I think you're pondering the same issues as many other Sigma camera users and it's the reason why the promised new full frame Foveon sensor camera is much anticipated.
I got into Foveon cameras through the DP2 Merrill which I still have and go back to for landscape and architectural photography. It is simply excellent along with the DP3M.
The Quattro cameras had a rocky start but many years later, SPP and firmware updates seem to have improved them considerably. The sd Quattro H undoubtably performs best with the Art lenses which are huge and heavy; the 70mm Macro Art being the exception as it's quite light. On the whole, my sd Quattro H delivers very detailed photos and has a better battery life, bigger buffer etc but they are still slow to use unless you put them in Low Res. Also, the have Super Fine Detail (SFD) mode which improves photographing the inside of low light buildings like churches. A tripod is needed and the files are huge.
The Quattro focuses well with the Art lenses albeit a bit slowly. I don't bother using third party lenses on the sd Quattro as I'm disappointed by the soft results whereas they seem to work nicely on a Sony A7 or Sigma fp.
In my view, where the Quattro falters is when there are lawns, grassland and some fine tree foliage in the shot. The Quattro often (but not always) 'mushes' these up into a blur. It's not a good look and I don't know why it happens. It's a bit Jekyll and Hyde.
For landscapes, I feel the DP Merrills are still a high bar but I really wind down the sharpness in SPP.
Saying all of that, my absolute favourite and most used Sigma camera is the dp0 Quattro. The lens is superb and I enjoy the wide angle challenge.
Below is a dp0 Quattro image of some very old Lancia Lambda cars. It gives an idea of the camera's output.

Below is a hand held stitched panoramic using the sd Quattro H and the 135mm Art lens at f/5.6 in Hi res mode. You need to be a weight lifter!

The Quattro cameras come in for a lot of criticism because they are not 'pure' Foveon but I like their outputs, so, continue to use them.
As for the little full frame fp, as you know it it's a Bayer sensor camera. The images are very good but if you want to count leaves in the distance, forget it. For me, it's greatest attributes are it's compact size and it works well with adapted lenses, in particular my M mount lenses. It's a good 'street' and people camera and focuses ok on the back screen with enlarging and peeking.

Here's a snap using the fp with a Zeiss Sonnar f/1.5 at f/1.5. It's a very narrow field of focus.

Good luck!