Well, the interest in "T12 technology" on the forum got my to buy some T12 stations. My initial impressions were mostly favorable. But in the end, there's no free lunch. One important aspect I couldn't evaluate on first impression was longevity. And after a only a couple of months of use, I can already see that clone tips are not up to Hakko standards. I have not tried genuine Hakko T12 tips, yet, but they seem to run the better part of $30.00 a pop from places like Tequipment.
The issues I have had with the clones
1. heater starting to die on my must used tip, after only 2 months. I have to admit, I have turned the station on/off more than usual, trying to take advantage of the super fast heat up time of my Suhan station, in particular. Which with the 24.5V PSU might put some extra strain on the heater. But this doesn't come close the cumulative abuse my T18 tips have taken over many years.
2. tips not taking solder as well as genuine Hakko T18 tips (which cost 8.00 each). My T18 tips hardly ever ask for a cleaning.. seems like I only clean them to remove burnt flux to prevent it from falling off onto the board. The cheap T12 tips seem to lose some of their love of solder after some weeks of use, even though I'm using the same temps and flux.
3. Tip finish/plating. Many of my clone tips have poor finish, surface irregularities, and/or cracks in the chrome plating I have never seen on a Hakko T18 tip.
4. Tip contact disintegration: well, I have to admit, I modified my handpiece, wrapping some tape around it to get the tip to fit more snugly so it couldn't spin. One of my tips got caught on removal, and the contacts on it ripped apart. That's on me, but on a T18 tip there's no durability issue to even compare to this.
Most of my clone tips still work great, but in terms of amount of soldering time, they are embryonic. The 2 I use the most have degraded noticeably in performance (one the heater;other the wettability). The T18 counterparts are still trucking after over 4 years of the same use with no degradation. Perhaps they even got better with age?
After using T12 for several weeks, almost solely, I finally got frustrated with the subpar wetting of the T12 BCF3. So when it came time to swap to BCF1, instead of swapping tips, I changed back to the 888 with the CF1. Even though I was doing delicate point-to-point rework with jumpers, I didn't even notice the longer tip to grip, at all. The main thing that reminded me I was using a different iron was when putting the iron in/out of the stand, where the familiar clunk and more positive insertion/withdrawal (without looking) made it feel like I was soldering with an extension of my own consciousness, or perhaps like I had just reattached a missing limb after weeks of fooling with T12 wannabe's.
I was also reminded of one quirk/feature of the 936 handpiece. When using tiny bevel tips it is sometimes harder to figure out what the exact angle is. With my 888, once the tip is locked down, I can quickly acclimate to the direction the tip is pointing by relation to where the strain relief has taken a set. With the 951 style, the strain relief is a shorter and it spins freely in the handle, and this reference is lost.