I actually broke 2 sched 40s as well. That insident resulted in me replacing the carpet and padding in a bedroom the first time and 6 hours of stress the second time. The sched 40 are strong enough, but you can end up putting some lateral preasure on them resulting on an internal moment they where not designed for. My first leaks was from me turning on and off a ball valve for water changes. After a while a ballvalve is tough to turn. Every time I turned the valve, it would tug a bit on the plumbing. Eventually this caused the bulkhead to crack as it doesn't allow movement. As a result, my 350 gal refugium and half my display tanks water ended up on the floor while I was away. The second time, I had a small leak on the bulkhead. Maybe a 1/2 cup a day. Gave the thing a slight turn to fix it which ended up in a steady leak. Spent the next 6 hours fixing that.
I like the sched 80 as they are gray and they are strong enough that I can typically reuse them a few times. You can also install them backwards without a problem or install a ball valve right on them and not worry about cracking them.
If you have a small tank then a cheap bulkhead is fine, but in my case if this part failed, I could have about 250 gal of water on the floor and a few thousand dollard worth of dead animals. Lets just call it an insurance policy.