The RJ45 plugs are some of the best I've found, and I certainly cannot beat the price. That said, while I've built many cables in the past, I've built 4 cables with these so far, and my 4th was the first to be free of a missing connection on a continuity test. (I highly recommend using a cable tester before attempting to use anything you build yourself, but definitely so with these.)
Trent P's review is spot on. I've had the same experience for the most part. Crimping is solid because the metal shield will crimp down onto the wire, which looks ugly but you have a nice solid grip. There's also plenty of room inside the connector for a thick cable. However, the other downside I found is that the back edge of the metal shield is thin with a raw cut edge, not folded inward. Thus, when pressed down by crimping, the edge can cut into the cable, possibly slicing into the twisted pairs. So, when you trim your wires, be sure the plastic cover and foil shield are being inserted into the metal shield to protect the TPs, and after, be careful not to bend the cable up into the shield, cutting any further. Once the boot is in place, that shouldn't be a problem.
I also agree with Trent P in that the wires inside feel too lose. The insert is not individual holes, and so you need the wires to be straight and well lined up before going into the insert, otherwise they will move on you during insertion into the main body. Also, the holes on the innermost part of the connector seem to be too wide, allowing the wires to move around and not make contact when crimped. Or possibly, the openings for the metal contacts are too wide, allowing the contacts to slide off to the side, instead of piercing the wire casing to the copper. In the close up picture, hopefully you can see what I do, that in this example, pins 3 and 5 are fairly straight, but all the others angle to the right just a bit.
Just a little more refinement, Monoprice, and you'll have it down.
These RJ45 plugs are a mixed bag for me. First the positive:
Grounding is SOLID on these jacks. Never made a connection with these that didn't have a good ground connection. Being able to wrap the outer support around the ground wire means this is a given.
the outer casing at the cable insertion end is ONLY metal. As a result, it is one of the few connectors out there big enough to fully insert the outer jacket of a shielded CAT6 or CAT6A cable.. This also means that there is not internal cable crimp that you would expect in a normal RJ45, so your cable crimper just dents the heck out of the entire metal underside of the metal part of the body. It makes for a very solid connection (which is very difficult to achieve with most shielded CAT6 connectors), but it looks a bit ugly.
The inserts (yes it does come with inserts) are pretty loose, and are basically a zigzag pattern across all 8 wires (rather than individual holes for each wire. The good news is that your wires sile into this realtively easily compared to a lot of other inserts. The bad news (at least with 23 AWG CAT6 (not 6A) wire, is that the wires are pretty loose inside of the insert. Because of the design of the plug, you NEED to keep the insert at the end of the wires because the connector itself DOES have holes for the individual wires, and the insert is the only way to get the wires into them. But because the insert is so loose, it can easily silp back while inserting cable into the plug.
I already mentioned the cons, but to summarize, the underside of the connection looks a bit ugly (not a problem if covered by a boot or f no one cares... good news, it is solid). Secondly, because the insert is loose, wires can get out of order in the insert, and slip back during insertion preventing a good solid connection.
These are by no means 100% fail-proof connectors for me. I find that you can trip your wires shorter than I normally might after placing them into the insert because you can stuff the cable farther into the plug. This also inhibits the insert from being as likely to slide back. Also, make sure that you keep the wires/inster close to the bottom (top of the jack when upside down) as possible to keep the internal "ramp from pushing back the insert. Finally, as tempting as it might be to make that good solid ground connection, and hold everything in place. I have had much more success crimping first and securing the cable support later.
With all of that said, for all of the annoyances and failed connections, I will likely get more of these for the advantages that they DO provide. until I find the elusive magic connector.