The "H" cartridge has all the stereo hits exactly like we know them. The "C" cartridge has many notable differences.
I will start by mentioning that on both Quad versions, instrument/vocal layout is completely different.
Here's a bit of a rundown of differences that I can hear:
1. Sooner or Later
- Alternate "Soul shouting" by Dennis Provisor, Missing Organ
2. Where Were You When I Needed You
- Not much could be done here *
3. Heaven Knows
- Missing handclap, Organ mixed lower, emphasis on guitars.
4. Let's Live for Today
- Again, not much can be done here *
5. Temptation Eyes
- Alternate Organ Solo, Double-Tracked Lead Vocals on chorus
6. River Is Wide
- Missing Handclap, Missing Piano entirely! Major emphasis on tambourine
7. Midnight Confessions
- Organ mixed down low, Stereo Brass Section, Slightly slower tempo
8. Come on and Say It
- The only item missing is Dennis' background "all right!" at 1:30. Identical to stereo mix otherwise.
9. Wait a Million Years
- Tambourine comes in much later in the song, like they forget to move the slider up
10. Walking Through the Country
- Different vocal take. Instrumental sounds identical to stereo version.
11. Lovin' Things
- Different Vocal Take, Percussion and rhythm guitar mixed higher
12. Things I Should Have Said
- Outtake. Different vocal track, accidental flub, different background vocals, different band track (Most notable difference: Drums! Rick was feeling creative on this take.)
13. Bella Linda
- Slower Tempo, early fade
14. Baby Hold On
- Early fadeout.
15. Feelings
- Identical to stereo.
16. I Can Turn off the Rain
- Vocals have heavy delay added giving a much richer vocal atmosphere. Possibly alternate vocal take, Instrumental track sounds identical.
I will say the "Alternate version" tape is a much more playful mix. Through-out the album, lead vocals are seperated and up front while background/harmony vocals are in the rear and duke it out front/back over the course of the tape.
* "Where were you" and "Let's Live for Today" were recorded on 4 track.