In terms of cost or value, NL Pure's are way past the knee of the 'value vs. cost' curve. Even gently used, NL Pure's typically run $2500 which is $1,000 more than the Leica Noctovid's I recently bought.
If you want to talk about Porros exclusively, there really isn't a viable market for "modern Alpha" Porro bins. We can argue whatever technical nuances we want to but, size, weight, technology, and low sales volumes will keep Porros from evolving in the mainstream with the technology we see in modern Roof bins.
Marketing and consumer sales, through advertising, has clearly focused mainstream consumers on small relatively affordable (on the cheaper end) roof bins as being the 'bee's knees' of goodness. Now that viable Porros are not in the marketplace, mainstream consumers only consider Roof bins without a thought about why they might want a Porror bin.
If you want to talk about Porros exclusively, there really isn't a viable market for "modern Alpha" Porro bins. We can argue whatever technical nuances we want to but, size, weight, technology, and low sales volumes will keep Porros from evolving in the mainstream with the technology we see in modern Roof bins.
Marketing and consumer sales, through advertising, has clearly focused mainstream consumers on small relatively affordable (on the cheaper end) roof bins as being the 'bee's knees' of goodness. Now that viable Porros are not in the marketplace, mainstream consumers only consider Roof bins without a thought about why they might want a Porror bin.