I had a magnefine on my Power steering return line. It weeped from the seam for years until I removed it from service when the weep turned to a drip. The magnet had not caught very much and the media looked pretty clean too. I've Been meaning to replace it. Probably say that in a year too.
I had one on my Tx which also weeped from the seam. But I'll admit to being a fool, and having it plumbed backwards as I made some false assumptions on the direction of flow. I'd urge others to follow the cooler line plumbing and know for sure which is the output and which is the return port on their Transmission. I got lucky that the bypass was not required as it would not have worked being plumbed backwards. Could have been a very costly false assumption.
I only realized I had it plumbed backwards when I opened it up, and found all the debris in the inside of the filter element and not very much on the magnet at all.
I had it on for years, but low miles, thank goodness the bypass was never required.
I now have a derale external filter mount for the TX with a fram ultra XG16 on it whose case is peppered ith Neodymium magnets. Its plumbed after the extra TX cooler which is plumbed after the stock radiator cooler.
I still have the magnefine magnets. While they are stronger than the original in pan magnet whch came inside my transmission pan, they are ridiculously weak in comparison to a Neodymium magnet. Whether that magnetic strength actually makes a difference is opinion, until hard data proves otherwise.