I've used the NTZ transprotector now for 5 years.....I cut one open after 50,000 kms or 30,000 miles and the internal micro filter was dark grey leading me to believe it was capturing small bits of debris. There is also a large magnet inside that also captures fine metal shavings.
I also noticed less material on the transmission magnet......I have over 200,000kms using these filters and if any one tells you they restrict fluid flow is all bunk. I've never had any problems......Even though I live in Canada I installed the largest transmission oil cooler that would fit on my condenser. The only problem I have is it take a while for the torque converter to lock up until the transmission fluid gets warm so I'm sacrificing some gas mileage...
I use ATF+4 fluid in my caravan and I drain the pan annually costing about $35-40 and the NTZ filter lasts me 2 years doing 25,000 km/per year. I now have 200,000 kms or 120,000 on my 2009 Chrysler transmission that still shifts like brand new. I've also used the Magnefine filter and never had seepage problems unless you open it apart before using it....if you do, make sure you seal the threads with some transmission silicone before reattaching. I like the NTZ better only because it's stainless steel and indestructible.....as I said I did cut it open and I can tell you it was no easy feat and had to use an angle grinder......I don't know anything about CVTs but the 2 thing that kills traditional transmissions is heat and dirty fluid. I had one caravan that went through 3 transmissions like most people I didn't do any preventive maintenance.
I had a 2000 caravan that I had for 15 yrs......I now have a 2009 and both still had/have the factory transmission and it outlived the vehicle. It amazes me how people quibble over the cost of transmission fluid...I know for the newer cars it can be upwards of $20/litre.....so change it annually and for $80-$100 you have very inexpensive preventive maintenance. As for CVTs, they cannot be rebuilt, a new one has to be installed.......you are looking at $4,000 +.
With any car or vehicle, even a small transmission oil cooler will reduce the fluid temperature.....if you are hauling any kind of trailer you need to get a large oil cooler. The heat will kill your transmission.