I have heard so many times in the past (all from customers) that the lighter the boot, the better it is. Well, true.. false... true... huh, how do I answer this? If a boot is lighter, it doesn't necessarily mean it is a better boot. The build may be lighter (composite toe rather than steel) and even the materials may be more breathable, but it is completely dependent on what the customer does as their profession. For instance, a mail clerk may be wearing his composite toe boot with a little leather and tons of mesh for three years. However, that same boot wouldn't last a week for a tile or mason specialist.
The best thing anyone can ever tell you when it comes to buying boots is "don't listen to the hype!" Understand exactly the type of work you do, and know how heavy duty a boot should be. A motorcycle enthusiast shouldn't wear a casual shoe like the Rocky Euro Traveller, he should wear the Chippewa Rally 27862 riding boot. Match your job with your boot.
The last thing I can leave you with is that sometimes all the bells and whistles are useless for a shoe. If you aren't required to have a safety toe or a waterproof boot, don't get one. More things simply add weight to the boot. A traditional welted sole will be heavier than a direct attached or cemented sole.
Remember, lighter isn't always better. The heavier the boot, in most cases, the sturdier the build. Steel toe, composite toe, aluminum toe or carbon fiber toe are all ASTM rated safety toes. Make the wise choice, go with what you know to be a good boot.