I like skip chains but I quickly learned that if I wanted one in my hometown in Kansas I'd have to special order it.
I was visiting my mother in Kansas when she remarked that it would cost about a thousand dollars to remove a dead tree in her yard. I'm not a logger or professional arborist but I've cut down a lot of trees so I took a gander at the one she pointed out. It didn't appear to be too risky (the city's "No Parking" sign was shaking nervously but there were no power lines, mail boxes or buildings nearby), so I told her that if we could come up with a big enough saw I could take it down.
My Stihl was lounging at home 1600 miles away and renting a saw proved impractical (none were available on short notice) so I did a little checking around. I found a new Poulan Pro with a 20 inch bar that would get the job done. It was priced at $199.99 plus tax.
I mixed up a gallon of fuel, filled the oil reservoir with bar oil and began cutting. Just to get used to the saw I first cut down a small tree that had died. The saw had a nice feel and cut cleanly and quickly through the wood. Once I had the tree down I began cutting it into stove length. The core of the tree was rotted out and about the third cut I hit a golf ball size chunk of cement that a squirrel (or one of the neighborhood children?) had dropped in the hollow interior. The chain was nearly ruined so I made a trip to the local farm store to purchase another chain. We looked up the number for the manufacturer's recommended chain but they were out of that one so the clerk recommended one that was a little more aggressive. I looked at it then asked if they had any skip chains. He looked at me somewhat surprised and said they'd have to order it. (I guess they don't sell many of those!) Then he said something that surprised me. He remarked that a skip chain was about the only way to get by with a 20 inch bar on a underpowered saw like mine.
Now, aside from insulting my saw (not a cool thing to do if you want to keep your customers coming back) he was a bit out-of-touch with the advantages of skip chains. He was correct in pointing out that under-powered saws use skip chains to make up for their lack of lack of muscle. However, he was incorrect that they wouldn't improve the performance of larger, more powerful saws.
In case you're wondering what a skip chain is look at the two photos below. In the top photo you'll see a "conventional" chain with a cutting tooth on every, other link. The chain in the second photo is a skip chain with a cutting tooth on every third link.
A skip chain has fewer cutting teeth than a conventional chain which means it won't be dragging as many teeth through the wood you're cutting. Less drag on the chain means less power is needed to cut through the log. That means the motor on your saw runs faster which keeps it in a more efficient power curve. It's the same principle you use when downshifting a transmission in your truck to go up a steep grade. You get more power by increasing the engine speed.
Most "mini-saws" (small saws with "thinner" chains and bars up to 14 or sometimes 16 inches) come with skip chains so there's seldom any other option for them.
Where a skip chain helps the most is in what I'll call a "homeowner's" saw. These are the brands commonly sold in discount and hardware stores and often come from the factory with a conventional chain installed. Bar lengths usually range between 16 to 20 inches long. I have two Homelite saws with 18 inch bars and one Poulan saw with a 20 inch bar. With these mid-size, "non-professional" (underpowered!?) saws, a skip chain is a no-brainer. Their performance improves dramatically.
Professional saws are where many question the need for a skip chain. These saws (Stihl, Husqvarna, etc.) have lots of power. I've had the privilege of using some large, powerful saws and they are awesome cutting machines. The debate for and against skip chains sometimes rages among professionals and, while the professional saws have adequate power for even the largest logs, one logger I talked to summed it up this way saying, "they just seem to work better with skip chains."
Another advantage to skip chains is that they are faster to sharpen in the woods. A 100 link conventional chain will have 50 cutting teeth. A 100 link skip chain has only 33. That's 1/3 fewer teeth to file when the chain gets dull. I've been asked if the skip chains need sharpened more frequently and in my experience the answer is "no."
If you've never tried a skip chain I urge you to give one a shot. You may have to do a little searching. Most discount stores sell only original equipment type chains so go somewhere that professional quality saws are sold. (Even then you may have to have them special ordered!) You may have to overlook a little snobbishness from sales clerks but the performance increase will be worth it in the long run.