Commuting - gears - what is the real difference?

Ok, I would like to confess myself a gear novice. I have cheap shimano cera gears, but what I want to know is when I upgrade to a better bike, what is the actual difference with the more expensive gears that for example, shimano makes? Is it weight? Is it range? I would like to receive your opinions.

Having progressed up through a few layers of Shimano I can tell you that you do get what you pay for. Each step up offers smoother, crisper, surer shifting. Having tried Dura Ace I will never buy anything other than DA shifters and derailleurs except that I still want to set up a bike with Campy. Now having said that let me say that I have 105 shifters and ders on my commuter. They work fine, and I don't plan to change them. The steps in quality/improved operation from 105 to Ultegra to Dura Ace are pretty small so I don't feel a need to upgrade the 105. But if you need to buy new shifters and ders, DA just isn't that much more expensive, especially considering you will be enjoying them for years. Since I don't mtb I'm not as familiar with mtb components except that I do have a Deore XT rear der on my commuter to allow use of bigger cogs. I see a distinct difference in quality between the XT and the next lower level LX so I would probably stick with XT there. XTR seems a lot more expensive.

I consider the shifters and ders the heart. Most other components don't make that much difference to me. Increases in price are generally just weight savings. 105 cranks, etc. work as well as any.

As far as range the main advantage of more gears is more options in the middle. You can find cassettes/freewheels in any configuration 5 speed, 6,7,8,9,10 with anywhere from 11 to 14 teeth on the smallest cog and 19-34 for the largest. But you do most of your pedalling somewhere in the middle so it is good to have several options in the middle range. My first 7-speed freewheel had 13-15-17-20-24-28-34 or something like that so I was pretty much stuck with, say, the 17. 15 was perceptibly harder and 20 was way too easy. My current favorite 9-speed has 14-15-16-17-18-19-21-23-25. So in the same range I could chose from 16, 17, or 18 to fine tune for how I feel, wind, etc.. Don't get hung up on having an 11 or 12. You will never use them. Even the 13 is more than most people need. I only use the 14 going downhill, if then.

Just one old guy's philosophy.
Regards,
Raymond

Yes part of it is weight, some of it may be range, but for the most part is is the performance and durability. For example with Acera you will never get the longevity of use in an off road situation as you would in LX. With XT you could go out and compete with the components and the shifter's and rear derailleur would last longer than LX. The weight between Acera and XT is noticeable in the hubs, brakes, bottom bracket, cranks, front and rear der.
Material usage will vary between Acera to XTR. By the time you advance from Acera to XTR the components are lighter in some cases stronger and will last longer. Since shimaNO has SO many different levels of components I would have to type a small book to explain all the differences.
In road groups it is the same. You do get what you pay for. However in MTB components for gears it does helpp to have a greater gear range in the back cogs. Since the front chain rings are smaller than road rings you can actually use them. I find when I am on my MTB's that I use pretty much the entire range in a given ride. Since I do not ride on groomed well traveled surfaces or even flat terrain, I use alot of gear's.