Purdy makes the best angled sash brushes out there. Even a complete amateur like me can load up the bristles and apply a smooth line of trim. This brush checks all the boxes for quality, value, and function. Yes, professionals recommend it and people out to spend a few quid to paint their own houses can make it look like a professional came by to help with ease.GOOD:Brilliant design makes this a brush among brushes. The handle is long enough for comfort and reaching fiddly spots between window trim and a corner where you have to perform acrobatic contortions to otherwise fit. You aren't forced to strap a foot of wood to your wrist like a bizarre splint or flail around like a kid playing at conducting a symphony.Paint goes on and stays on. I've used semi-gloss trim paint, satin and eggshell by Sherwin-Williams and Benjamin Moore. Their formulations help reduce streaks, but it's really the brush that works the magic. It spreads paint out evenly and allows for delicate applications without clumping up or dripping. The length and size allow for control without covering only a narrow strip of space. It's an all-around great product.BAD:The bristles retain paint so well that it takes considerably more effort to clean the paint out. A small quibble but an important thing to note. You'll need more elbow grease, but the results are worth it.