Few pieces of gear are perfect, although they are getting better all the time.  Many pieces of gear have to make trade-offs like weight versus some safety.  Let's take helmets for instance, the gold standard would be a motorcycle helmet.  I highly recommend taking a very close look at how they are constructed.  The padding is exceptionally thick and protects a very wide range of impacts.  Their helmets undergo extensive impact testing to meet federal standards.  Sellers are required to make certain the helmet fits perfectly before you leave the store.  Why don't we use motorcycle helmets for kayaking?  They are heavy and very prone to mildew.  In recent years, we have adopted the full face concept though.

PFDs have changed over the years as well.  Older vests had far more buoyancy and many are still in service for that reason.  New vests are much more streamlined and have many nice features like ample pockets to safely stow extra gear like a small throw bag, rescue knife, or carabineers.  The price of rescue vests has dropped considerably making it hard to justify purchasing a non-rescue vest.

Thermal protection has gotten far less expensive.  A dry suit used to be a luxury item - now it is common place.

Boats have far more safety features like walls when needed or very rigid plastic as on Prijon boats.  Most river runners have convenient grab bars right behind the cockpit, something only good creek boats had in years past.  Cockpits are huge compared to the keyhole cockpits I started with.  If your boat lacks a decent hand hold on the end, I highly recommend adding one with climbing webbing.

Ropes have various trade-offs as well.  A full size rope may be too large to fit in a play boat and too heavy when wet.  On the other hand, they can't be beat in serious rescue work.  Polypropylene ropes handles exceptionally well, floats, and stretches - all great features in traditional throw bag work.  On the other hand, it isn't very strong and has a low melting point so it might not be suitable for unpinning a seriously pinned boat.

During our class, we will discuss pros and cons for many different features of gear.