If you have big construction jobs to do, or lots of plywood to cut, you might consider a worm-drive saw for more power and faster cutting. With the motor mounted behind the blade, worm-drive and hypoid circular saws use oiled gears that make them more powerful than sidewinders. Worm-drive saws need regular oil changes, but the newer hypoid saws have permanent oil, with no changes ever needed.
Worm-drive and hypoid saws are heavier, so they're more tiring, but the extra weight can actually be an advantage in guiding the saw on long cuts, and you can tilt the work to let gravity help. Since the handle is behind the blade rather than beside it, you have a longer reach -- useful for cutting plywood and other sheet stock, as well as when reaching down to the floor or up overhead. Tom Silva at "This Old House" notes that since the handle is further from the blade, you get a little more margin of safety from kickback. Reviewing worm-drive saws for Fine Homebuilding, Scott Grice agrees. Many framing crews love worm-drive saws as timesavers, and most come with convenient rafter hooks.
For many years, the Skil worm-drive saws led the market, and the most recent review, in Fine Homebuilding's January 2008 issue, gives top ranking to the 14-pound Skil MAG SHD77M (*Est. $205) with magnesium housing, praising its comfort and power. Owners reviewing it at Amazon.com and Home Depot give it mostly high praise, but the Journal of Light Construction finds that the base plate can bend from just a short fall from a sawhorse. The Skil MAG saw has other drawbacks: It bevels only to 45 degrees, its blade guard sometimes gets hung up, and reviewers say it kicks quite a bit on startup.
Ridgid R3210 (*Est. $170) bevels to 51.5 degrees, though Fine Homebuilding says it's hard to adjust past 45 degrees, especially with one hand. Another drawback is that the base plate lacks rolled edges for strength. Still, reviews say it's well balanced, even with its 14-pound weight. The Ridgid R3210 ranks third in the Tool of the Trade Online review, which praises its 45-degree detent, big adjustment levers, sizeable markings and excellent blade guard. Its lifetime warranty is another plus.
The Bosch 1677M (*Est. $220) is similar to the Skil MAG saw, but it bevels to 50 degrees. The Fine Homebuilding review prefers the handle arrangement on the Skil, but says that otherwise, the Bosch is fine. However, the Journal of Light Construction says the depth adjustment didn't work well after the saw was dropped a few times. Reviews say this is also a problem on the Makita 5277NB (*Est. $140) hypoid saw and note that the base plate doesn't seem sturdy enough. Both saws carry one-year warranties.
The lighter 13-pound DeWalt DW378GK (*Est. $200) hypoid saw is the first choice in three comparison reviews, including Tools of the Trade Online and the Journal of Light Construction. Even the Fine Homebuilding review, which criticizes both the handle and power, agrees that blade-guard performance is flawless. Editors at the Journal of Light Construction like this saw's balance, and Fine Homebuilding notes that people familiar with using a sidewinder saw will probably find the DeWalt easier to use than most worm-drive saws. Its light weight and handle position make it especially good for overhead cuts, and it carries a three-year warranty. Overall, if you need the extra power of a hypoid or worm-drive saw, most reviews say the DeWalt DW378GK looks like the best choice.