Hi,

I fully agree with you. An important part of my white repertoire is based on IQP positions:
- Alapin against Sicilian
- 2.c4 against Caro-Kann (John Emms: Attacking with 1e4)
- (Denis Yevseev: Fighting the French: A New Concept against French)

It is more important to know the plans and ideas in the IQP position and the pawn formations that can arise (hanging pawns,…), rather than knowing all the variation in the different subsystems.
I play the IQP positions my whole chess life (from 0-2300 Elo) and make a lot of points with the IQP only to the fact that I am more familiar with the middle game positions that can arise.

I can really recommend the book of Denis Yevseev. Although I don´t have the same opinion in each line he gives, the chapters with the IQP positions (i1-i7 in the book) are really good and a nice starting ground for own analysis.

I am really looking forward for the new IQP book by John Emms:
http://www.everymanchess.com/chess/books/Attacking_with_the_Isolated_Queen%27s_P...

Kobalia - Jobava, Plovdiv 2012 was a model IQP win by White which emerged from a Panov Attack.  It is well treated in the latest update.  Personally I think that the Panov is an excellent practical try against the Caro.  It really doesn't matter if they see you coming; you just have to be able to play White's side of the IQP.  Theory is theory, but Black's life is not so easy with the clock ticking.

Similar positions arise from the QGA, the Semi-Tarrasch and the Nimzo, so I think good facility with White's side of the IQP could be the basis of a repertoire that included both 1.e4 and 1.d4.