Chess Puzzle Book - For Analysis Not Just Tactics?

Hi, I'm looking for a new book to improve my chess play. I already study tactics with CT-ART 6.0 and I thought the best way to improve would be to locate a puzzle book that deals in analysis. 

In other words not a traditional chess tactics book, where there's a decisive tactic present (I already have that with CT-ART), but more open ended problems with less clear solutions followed by explanations and analysis that would, at once, deepen and improve both my chess understanding, vision, and calculation ability. Seems like a good way to go, no? I'm ~USCF 1800.

I thought I'd share my research on the matter, and ask for advice. Such as: Has anyone read or studied these books? Has anyone else reached the conclusion that performing Chess Analysis Puzzles in addition to tactics is beneficial and a good study method/the way to go? Have you had any success using this method?

My list:

1. Imagination In Chess By Paata Gaprindashvili

My observations: I think this one might be too challenging for me. I approximate myself at USCF 1800. Seems like a good book, though, once I hit the 2000-2200 level. A very good book that apparently has a cult following. 

2. Critical Moments In Chess By Paata Gaprindashvili

My observations: I can find very little written on this book. One reviewer guesses that it would be easier than Imagination In Chess because it has lengthier explanations. Can anyone confirm? This book is in the running for my next purchase. 

3. Perfect Your Chess by Andrei Volokitin

My observations: Looks awesome. But again, too quirky or difficult for my level?

4. GM-RAM: Essential Grandmaster Chess Knowledge by Rashid Ziyatdinov

My observations: Again, way too difficult and no solutions!

5. Practical Chess Exercises: 600 Lessons from Tactics to Strategy by Ray Cheng

My observations: Player isn't overly strong. This concerns me. 

6. Masters: Boris Spassky Master of Initiative by Alexander Der Raetsky, Maxim Chetverik 

My observations: Now this one has recently come to my attention. It's a look at a player through puzzles. Very intrigued. Anyone try it? or another one of Raetsky's books? They are apparently all puzzle based. 

7. The Best Move by Vlastimil Hort, Vlastimil Jansa, Lev Polugaevsky 

My observations: Actually looks pretty good. But apparently the newer edition is rubbish and the older copy has a high price!

That's what I have right now. Would appreciate any feedback to my questions or this book list. Or any additions or any comments. Once I can figure out which chess analysis puzzle book to invest in, I'll report back with my review. 

Thanks so much,

harmless64

Anyone?