I am always researching long and hard to see what equipment might improve my enjoyment of filming and the quality of my product (wedding films). I take my time over decisions as there is new gear coming out every month =) As I am running a business, whenever I get excited by new gear I ask myself the following questions: – Will it make my work flow more efficient and therefore save me time/money? – When will I see a return on my investment? – Will my clients notice the difference in quality, and therefore is it likely to secure me more/better jobs? Last year I filmed nearly 20 weddings with a GH3, GX7 and GH2. Unfortunately after 3 years my GH2 has died so I am in the market for a replacement as I find 3 cameras essential for certain parts of the day. I could get a GH4 as my new main camera, another GX7, the rumoured EM5 MkII for IBIS if Olympus can finally deliver a great 1080p codec, or I've even thought I could go for the Canon C100 MkII (partly so I could finally see for myself why so many people fuss over Canon!). From a technical perspective I'm not sure the speedbooster + sigma will improve your image quality much, unless of course you find yourself needing to use high ISOs in the studio and therefore the speedbooster + sigma at f/1.2 would help. Ultimately I would try and make the decision based on your business goals. You might decide your clients are happy with what you produce now and you can invest the money differently! Hope that helps =)