My thoughts on tracks that spring to mind:

As mentioned above the stereo mix of the Four Tops Reach Out is very poor given the classic nature of the song, BG should have forced a remix! For example, just listen to how the tambourines are louder at 0:44 for the duration of the section then at at 1:32 they are louder for only half of the section and then at 2:36 they are not louder at all for the section. The mono mix is much more even sounding overall.

I hate the stereo mix of There's A Ghost In My House from the very start with the overbearing backing singers and weak drum presence in the mix. The mono version is so much more "driven".

I also hate the stereo mix of Walk Away Renee with the intrusive piano that doesn't gel with the song. Like 'Ghost. the mono version presents the song much more effectively.

The stereo version of Going Down For The Third Time is almost unlistenable to me in comparison with the superb mono version. However, Diana's voice should have been more upfront in the mono mix for it to be ideal but it's fantastic overall - should have been an A-side.

The mono mix/edit of Stoned Love is very well executed in terms of clever reuse of an segment of the song and the clarity of the handclap and drum sections of the song. With the editing being barely obvious it's a shame that the violins come in so abruptly with the final edit at 2:23. The stereo version just doesn't seem so focussed in terms of the overall mix to me.

I prefer the mono mix of Road Runner on the Ultimate Collection to the mono mix on the Hitsville box set and the 2 stereo mixes that I am familiar with. The Ultimate Collection version has so much more presence to my ears.

The mono mix of You're All I Need To Get By [[Marvin & Tammi) has a superb overall quality of voice to instrument sound levels. Whereas the drums on most mono mixes are more prominent they blend in with the other instruments and vocals in a way that totally suits the overall feeling of this song. The stereo mix is just ordinary in comparison.

The mono mix of Back In My Arms again on the Ultimate Collection has so much more presence than either the stereo or the mono mixes on the expanded More Hits.

The mono mix of Come Round Here I'm The One You Need has much more presence than the weak stereo mix.

The mono mix of Love Is Like An Itching on the Ultimate Collection has much more presence than stereo mixes of the song. Perhaps down to difference reverb levels?

The mono mix of Reflections has a "lag" at 2:30 whereas, what seems to be an edit, it is much tighter on the stereo mix. Overall, for once I prefer the stereo mix!

I'll have a think about other songs