From a plumber's viewpoint, they are expensive since they typically have the tools to use a simpler fitting and already have either the expansion tool (Uphonor tubing) or a crimping tool (all of the others - I prefer Uphonor and I think that's what you have there now). So, maybe a buck for the fitting verses five for a sharkbite...it adds up quickly. But, you can't buy the tools needed to either crimp or expand to use a conventional fitting for what you'd spend on a couple of sharkbites. Then, the seal is dependent on o-rings - there are teeth that hold the pipe in the fitting for the o-ring to seal. If you don't use the tool to deburr the edges (about $10), you could slice the o-ring and the fitting will leak (a little twirl around the end with some sandpaper should take the burr and sharp edge off - this puts a microbevel on it that protects the o-ring during installation - the tool does it quicker with a small metal cutter). While not an issue here, since the fitting is sealed with an o-ring and teeth in the soft plastic, the fitting can rotate a little (you can rotate it on a barbed crimp or expansion fitting, too). If the pipe moves, a crimp or expansion fitting may be better, but it's a good idea to anchor the pipe regardless of the method of installation. Bottom line, is first cost, then the 'fraility' of the o-ring. Now, the things are code complient, and work...but, there's more room for error. If you make sure you have the tubing anchored and you don't mess the o-ring up during insertion, it should last forever.