Over the past year and a half I have made several changes to my "gear philosophy".
I started out 2014 with an EOS 5D Mark II and an EOS 7D. I sold the 5D Mark II, a decision I regret. I had a Canon EF 24-70mm f/2.8L lens and an EF 70-200mm f/2.8L IS II lens. The latter I purchased by selling my non IS 70-200mm f/2.8L and my 300mm f/4L IS lenses back in 2013.
I sold both the 70-200mm and 24-70mm lenses and I then bought used Sigma 50-150mm f/2.8, 17-50mm f/2.8, 30mm f/1.4 and 10mm f/2.8 fisheye lenses.
I don't have anything bad to say about the Sigma lenses other than that I much prefer using Canon's DPP software for processing my images and that just doesn't work to get the best out of images made with Sigma lenses. If I were just shooting JPGs out of camera I would have been happy with the Sigmas but I shoot RAW and process every image to get rid of chromatic aberration, something the Canon software won't do with third party lenses.
So, starting this past Spring, I began a reverse migration back to Canon lenses. I sold all my Sigma lenses for pretty much the price I paid for them. I then picked up a used non IS 70-200 f/2.8L at a great price on eBay. After experimenting with primes in the barely wide to short telephoto range I picked up a used 24-70mm f/2.8L USM lens from Adorama. In fact, this copy of the 24-70 was made in 2011, the last year Canon made the lens and is in better condition that my earlier copy.
So, I am now back to where I was with really nice 24-70mm and a 70-200mm lenses but with only crop bodies. The addition of the Canon EF-S 10-22mm f/3.5-4.5 USM back in the Spring, a lens I really like, compensates for the lack of a full frame body.
So, I'm heading into the future with two 7D bodies, one with battery grip, one with Magic Lantern software and a 70D body together with Canon zooms covering 10-22mm, 24-70mm, and 70-200mm in addition to 24mm pancake and 50mm STM primes, Canon's EF-S 60mm macro lens and an extender 2XIII.
The EF 28mm f/1.8 USM and EF 100mm f/2 USM lenses are expected to be sold in the near future. Here are the seven lenses, without hoods, which will now remain in my main bag.