Pros - Tank of a headphone - nearly all aluminium, earpad locking mechanism, folding mechanism, expansive imaging, clear mids and treble, super efficient
Cons - heavy on the head, odd bass presentation (subjective)
First of all the build of this headphone is superb, almost all metal that feels very durable and solid, unfortunately it is rather heavy despite some plastic parts on the headband to reduce weight. Overall it is still a good step above the already good V-MODA M100 in the DJ catergory in terms of build. It also has dual socket entry and you can remove the plates (unfortunately Philips doesn't offer customization of the plates, only Armin himself gets them apparently). The headband is covered in some type of leather, but the padding is rather hard. However they are quite comfortable, just not for the longest of sessions.
I like the slight upper mid emphasis, lower treble has just the right amount of energy, high treble is smooth yet has some sparkle, the bass however has this odd character like the V-MODA M100 has it is just slightly thick and slow with not enough texture (although some people will say it is tight, but I like sets like the B&O H6 that have less upper bass but textured sub bass). These do have good bass that rolls off slightly in the very deepest of lows, it is still there just not as present. The A5Pro sounds uncongested fairly open and lively with great layering and imaging. It might not be super wide, but it can put some distance between the instruments and place them around you.
another plus of this headphone is that it is driven very easily by everything.
I would suggest to get the "i" version which comes with a shorter cable with a remote (unfortunately this cable is stiff and always curls itself up to its original shape it came in the box). But the coiled cable is huuuge for portable applications and the connector very large.
I can't quite put my fingers on but they do have some splashyness mid treble but it is nowhere near as annoying as the M50X. Also the Imaging is better than M100, M50X or K267.
If it wouldn't say "Philips" on it this can would go for 400 bucks and people would still say it is good value. At 160 to 250€ where it sells here (299€) initial retail it is a great option.
For such a large over ear headphone it also folds into a small shape with you can sort of fling open in an instant as showcased in various marketing videos which is pretty cool.
Bass is satisfying for outisde use but be aware that it has 3 ports on both sides hidden behind the arm of the fixture to the headband that makes the isolation, soso, still better than M100 but not as good as HD7DJ from sennheiser or HD25.
there is some nice quilted pattern detailing on the cable and parts of the headphone that give it a modern sporty look.
The only real downside to me is the bass character, feels strong, heavy presence, yet doesn't hit hard or move much air, it is more about hearing bass than feeling bass, it is enjoyable in its own way, yet just a touch unusual compared to other headphones.
I was looking for an alternative to my PSB M4U1 as they are a bit strident in the treble. I won the A5 Pro on ebay for £70 and I am very pleased with them.
Comfort - after 1 and a half hours the top of my head aches a bit from the lack of soft padding on the headband. Not a problem since I would have a break. Clamping force is very secure and is not a problem for my small to medium sized head. The lead is just long enough at 1.4m stretching to 3m
Sound - There is a nice smooth and defined mid bass and slightly less sub bass, not quite as much mid bass as the open Philips X1 but cleaner sounding. Punchiness in the mid bass is very pleasing, giving a very accurate, controlled reference. Mids are very slightly dark and non fatiguing, bright enough for clear vocals and guitars, detailed and clean. Treble is very natural, there is a smooth curve with good extension that is clear and yet not fatiguing, indeed the treble is far more pleasant and natural than my PSB M4U1 which is strident. Mids are also slightly darker than the PSB, but neutral. I have also compared the Philips with the Sony MDR-100AAP and the Philips has more detail across the board, punchier bass (not quite as much sub bass) and better imaging. The A5 Pro handle all the genres that I like very well, be it jazz (pianos sound great), rock, pop or dance. Newer dance music cds really show what the A5 Pro can do with punchy bass and detailed sound. With good quality headphones you need to have good quality music as opposed to compressed mp3s to notice the difference between good headphones and cheaper ones. Comparing the PSB M4U1 to them is that the PSB has less bass impact, harsher treble, slightly wider sound stage and more comfortable.
Summary - Not sure if they are worth the £300 rrp but on ebay you can get these for around £100 or less which is an absolute bargain, hi fidelity listening at a budget price. Maybe the likes of the Bowers p7 can offer slightly wider soundstage but other than that I don't think you can get better sound quality unless you spend £400 or more.
UPDATE: I got fed up of the discomfort from the headband which was not padded enough, so I sold them after having them for about 2 months.