I'll start this with the following disclaimer: All locking pliers of all brands inherently ****. It's a compromise by its very design, and they will wear out and eventually become welding leads or scrap, depending on mode of failure. The most important thing to stress is NOT to hold something with locking pliers, and impact aggressively against it. It jostles the pliers, and the vibrations help wiggle the work piece free. Anything more than a little 3/8 m12 impact (50ft/lbs max?) and you're going to be risking the pliers slipping.
The imported Irwins are okay, failure mode is typically teeth rounding over. They use the ****** release design though, which IMO means they're a non-starter. Tekton seemed to remedy this, but making a better quality jaw and the much nicer "pull to separate" style release. Issue being with daily use, the rivet which hold that release lever on fails. IMO the metal used is simply too thin in that area, one of the heads falls off one side and your release lever is on the ground. Shame, because they're a nice well gripping unit. Simply not up for daily use in my mind. Bollman grip, sold on HJE, is a hidden value. Good tooth material, the biggest downside is the shape of their curved jaw models, which is shallower than the typical design. It's not a flaw, but one needs to slightly adjust how much you open the jaws and how you apply then, vs the "normal" design. AVOID the long nosed angled pliers with the thin nose. They are utter garbage and the german who designed them should be shot. They're worthless as welding leads, they can't even grip properly to ground a welder. If you want narrow locking pliers just buy the snap ons, they work properly. Knipex makes locking pliers, they have worked well for me, and have some very interesting jaw designs available. I should buy more to get a better opinion.
For specialty options, Engineer is a great buy. They're nice for smaller and oddly shaped things. That said, their trade mark tooth design means in certain situations you're actually decreasing tooth contact area in a particular direction. If you were going to own but a single brand, engineer should not be that brand. They are a fantastic product for grabbing things straight on with the teeth and smaller items in general.
My preferred brand, is grip-on, rebranded by proto, snap on, maybe others. Most of mine are proto branded with a few snap on and grip on branded ones mixed in. Good jaw wear, and really like their parallel jaw models. Big downside is lots of their products come powder-coated, so they're useless as welding leads when they wear out.
One thing to remember with locking pliers is to not let things spin in the jaws. The number one way to utterly **** the teeth on any locking pliers is to grip down on something, like a sway bar link joint, put your 1/2 impact on the other side, and spin the joint at 1000rpm through the jaws. The other thing is to use heat whenever possible obviously. Make it glow, THEN apply locking pliers.
