What is so special about PD-14 that the West doesn't have?
Can you explain this in layman's terms?
Well, development of any large high bypass turbofan is something extraordinary. It probably took thousands of engineers and specialists working for many years to develop this engine, with a development cost measured in billions of dollars. Only a handful of companies in the entire world are able to achieve this.
But, if you compare the publicly available specs for PD-14 to a similar size modern engine such as LEAP, you'll find that while the PD-14 engine is competitive, it's not anything that will have P&W, GE, or RR too worried.
There are also several key parameters that are not publicly available, such as the manufacturing cost, purchase price, the lifetime of the major components (i.e. how many flights before you have to replace the turbine blades), the cost to repair the major components, and the reliability (how often to you have to cancel a flight because something broke just as you were loading passengers). Because this data is not easily available to the public, I'm sure they will claim it's great, but there is no easy way to verify. Probably they are comparable in all regards and it's just marketing spin.
Its main advantage as far as I can see will be its comparative simplicity even if it falls a fraction short in terms of Specific Fuel. They claim its cheaper to produce and cheaper to maintain. Durability and reliability will be the big questions. Its estimated price has been released. Far cheaper than Western Equivalents. Less than half from memory. They have gone very quite in recent times. Aeroflot must be confident. Apart from there first deliveries all there subsequent aircraft are now going to use the PD-14.