I have quite a lot of the Illamasqua brushes so was eager to buy their new Angled Eye Liner Brush (£15). Its quite a bit smaller than their brow brush, although the brush textures are very similar. The brush is very firm but does not feel harsh against the skin. Compared to the MAC 266 (which I used as my main angled liner brush) there is a lot less give in the Illamasqua one, and it keeps its shape, whereas the MAC one frays out a bit. The angle of the MAC one is steeper. In terms of performance I find that the illamasqua one gives a more precise line, but I can get closer to the lash line with the MAC one.
Pictures of the three to compare (angled one on top).
Its a nice addition to my ever increasing brush collection, I really like Illamasqua brushes, my stand outs are still their powder brush and blush brush 1 though.