PoF is okay. It's definitely more liberal than more popular dating sites like eHarmony and Match, but it also has some of its own flaws (like everything else).

The user interface is quite clunky, but the core functionality works and works well. Searching is pretty flawless, and there is a handful of pre-created categories to browse from. They seem to have strict rules on profile shots, though I'm unsure of how stern they are with them. They also claim to have a mobile variant of it, but every time I've used it to read new messages, it would be the same interface as the main site.

It's matching algorithm is pretty poor. Most of the people I'm matched with are terrible matches for me, at least by profile description. Some of the women I was matched to share very little with me and many that I've initiated conversation with have been very dull at best (at least initially; they could be very different with other people, but that's from my experience). They also have really useful categories, such as users most likely to reply (which is new as of this time of writing) and users who haven't received mail in 24 hours. On a more personal note, I actually recommend searching through these categories FIRST since most of these people haven't gotten too bitten by online dating yet and will be most likely to respond (though there are several more hideous profiles to be found in there as well for the reason).

Messaging, on the other hand, works extremely well. Reading and responding to new messages can be done with one to two clicks (for those that care about those sort of metrics), and one can view the responder's profile and other information right from the message page. Each sent message also has a read/unread/deleted status, which I feel is pretty controversial (and has worked against some users, though they also allow profile blocking to handle edge cases). I think that an interested/not interested status would be more informative, though I suppose discerning that from conversations (or lack thereof) is more natural.

The meeting process is completely unassisted, unlike Match and eHarmony who guide a person through each step of the way. I prefer PoF's approach more because it is so much more realistic, though I have heard that the assisted methods used by the other sites increase the guarantee of a good date happening. Personally, I haven't gone out on many dates from the site, though I've had MANY more conversations go nowhere instead (hence why assisted approaches might work better, since they also facilitate the phone calling stage, which can make a HUGE difference between a fade out and a first date).

Finally, they have forums, which are fantastic and ripe with useful and insightful information...if one doesn't post in them. For some awfully strange reason, any post that a user makes on any of the forums there are summarized and linked ON THEIR PROFILE. For avid PoF users, this probably works well and establishes a sense of community. For the many many MANY others that are not, it reeks of desperation and just doesn't look good. Worse, those links cannot be deleted! I tried to ask the admins to remove them to no avail. I think I had to abandon a profile because of this. I've also heard of their heavy-handed moderators and willy-nilly profile deletion, but I haven't experienced either of those yet and cannot comment.

In short, PoF is quite excellent for a free service, but would be uncompetitive against the eDating titans. Too many small issues. Its founder, however, is quite ingenious and brave for continuing to make all of this free. It's a wonderful service and plenty of fun when bored and single!