My children, well my eldest son for now, have inherited my Sci-Fi and fantasy troops as I was running out of space in the loft so they surreptitiously "moved into a downstairs bedroom" (I should really call it a tactical loan). I have never fought a Warhammer 40K with my "own" troops but have enjoyed an intro squad game at a shop (they were very complementary about my Tyranids). The one club game I once played was with other peoples toys (Orcs [me] versus Chaos Space Marines) and frankly was a terrible experience, as I was one half of a historical gamer pairing trying to understand the system, thankfully some "grown-up" (middle-aged) teenagers came over to help and salvaged something. I didn't even get to do a proper "Waagh" ;)
My hope is to recycle these troops 'character' into exploring "The Black Fortresses" (modern versions of the Space Hulks to my mind) akin to move-style horror RPG. I'll mix in other ranges. So although for 90-95% time I enjoy ignoring GW, I still like that they are there - particularly as I will freely borrow from their paint ranges and techniques.