Without a doubt, Real Techniques have taken the place of most of my MAC brushes, and I'm developing a bit of a habit...
Both brushes are made with taklon fibre so they're super soft, I could just brush them against my cheek with nothing on and that would be enough to justify the purchase. They also receive bonus points for their 100% cruelty free status.
I find that the Blush Brush gives a much softer application than my MAC 129 brush, therefore it's been perfect to apply any matte blushes that I have (I'm talking MAC Fleur Power, Frankly Scarlet etc) as it creates a much more diffused effect. I'm not so keen if I want to whack on a bit of shimmer though, I find this works against itself and doesn't apply enough product if I want to pack it on.
The Expert Face Brush was a completely novelty purchase. I have a multitude of densely packed foundation/cream blush brushes and I really didn't need another one. It's a lovely brush and I love having it in my brush pot (not a good reason to buy a brush) but I really need to find a proper use for it. I have a serious RT Buffing Brush habit when it comes to foundation or liquid concealer and my Sigma F82 has monopolised the cream blush corner. I've tried the brush for both of these uses and I'm still happier with the alternative. I might give this a whirl with foundation as it's the only thing I haven't tried it with yet. I still adore it though!
Overall, if you factor in quality and value, you really cannot go wrong with the range. I certainly haven't had enough yet and I see more in my future...if I can justify it! #beautybloggerproblems.