I have just the opposite experience with them. The only ones I use are from Home Depot. RL Flowmasters in the one and two gallon tanks with the pressure relief valves. I have one with Round Up and one with Weed Be Gone with me at all times. I leave the chemicals in them from year to year and no problems. I even drive past Lowe's, Ace and other stores to get them at Home Depot. Sorry you haven't had the same luck.
Coral Lawn Care
JD 797 Z-Trak 72" Deck
John Deere G-15 WB
Echo PAS-260 Power Heads
Echo Trimmers / Blowers / Edgers