He bought two old frames that had probably been abused and left to rust long before he got his viscous claws into them, then he abused them until they failed and is now using that as an excuse to defame older frames
Oh okay, methinks I dost exaggerate in a feeble attempt to make a point.
OP, steel frames are good, strong and reliable ... until they are abused and neglected though you should understand that aluminium and crabonfibre are far less forgiving. You're either monumentally hard on frames (in which case you should only buy Surly steel frames) or incredibly unlucky (in which case sticking to Surly isn't a bad move either). Regardless of what the causes are, only a fool would decide that steel frames are not up to the job, they are actually far more forgiving than any other material.
So, before making decisions about what to buy, work out WHY you broke two frames. Hint, the frame material is not the answer. It's probable that you simply bought much abused frames in the first place - buying new will negate that problem. It's also probable that you abused said frames, even if you didn't realise it at the time. Bikes are not tanks or bulldozers and resent being treated as such.
I think you're on the right track in buying a new frame, though I'd urge you to expand your choice of frame material before making a decision (it's not the material that matters, it's the design and construction of the frame that matters). There's nothing wrong with the Leaders, they've got lots of followers on here, but so have Surly, Wabi and other brands.
However, I'd also strongly suggest you review how you treat your bikes - it's possible you aren't hard on your bikes and were just unlucky, but it's bloody hard to break a frame, even when trying to. Avoid potholes. Don't go kerb hopping. If you like pulling wheelies, don't slam the front wheel down hard. And so on.
Just my thoughts but hey, what would I know, I weigh 110kg (240 pounds), commute on roads that could be generously called 'okay' and ride a bike I bought new in the eighties ie, it has one of those ghastly flexy steel tube frames and is now 30 years old. I'm also a grumpy old sod
