I have owned more then one, CZ70, CZ3d, CZ5 I swapped it back and forth from the three. I also have one for my GT&i1500. They are tough and rugged. I have yet to have one break on me. With sensitivity set at 4 on my CZ's & 8 on my GT&i, the inline probes would consistantly hit coins at about 3".
Are there drawback to the inline probes? well certainly, it does add a tad bit more weight, but it's less then a half pound, The probes take a little getting used to because unlike most probes, which only detect at the tip, the inline probes detect almost the full length of the probe shaft shaft. But the main annoyance to me is I keep forgetting to switch from probe back to coil until I swing for awhile and realize I aint hittin no targets and check. sure enough, forgot to switch it back.
Now, the other upside to the inline probes, is they are basically a 1" coil, you can use them to get under bleachers at sporting fields, I have even taped mine to the lower rod of my CZ70 and used it as a small probe around areas with a lot of metal around.
To me the probes are worth the $179.00 investment and if you check on the classifieds, you can mostlikely pick one up for around $125.00 or less.