After seeing these racquets initially a few months ago, I was skeptical as to the real changes that were made.  There have, of course, been manufacturers that have merely changed a color scheme and released a racquet as if it was going to improve the consumer's game.  After an initial hitting session with one of the updated racquet families, I can say that I notice the new technology.  With the overwhelming popularity of the YouTek technology, Head made a good choice in not taking that away with for the 2011 line.

Instead, what Head has chosen to do is take the platform of the previous models, and add in a new (to the tennis industry anyway) fiber known as the Innegra fiber, which is integrated into the YouTek/d3O graphite matrix.  This fiber was originally created by Innegrity LLC for use in surfboard manufacturing.  The Innegra fibers exhibit very low density with a high modulus, which provides impact resistance and strength without increasing weight too much.

When applied to racquets, these melt-spun Innegra fibers increase the rigidity of the frame a bit, resulting in greater stability, while the fiber flexes more than typical graphite.  The additional flexing and movement of the Innegra fiber helps to dampen frame vibration, resulting in a better feel and more comfort.  An advantage of this material is that it offers these characteristics, while being lighter than most materials utilized in racquet manufacturing, so the racquets needed to be adapted very little to compensate for the addition of the Innegra technology.

Two racquet families in the Head lineup get the initial Innegra treatment, as well as a few changes to the family.  Both the Speed and the Extreme lines receive the new technology, along with new paint schemes and a few model changes.  For example, the Speed line gains a new, lighter version called the IG YouTek Speed 300, which weighs in at 10.6 ounces compared to the 11.1 ounce weight in the other Speed MP versions.  In order to make room for this new, lighter Speed, the beefy, Speed Pro is gone from the family entirely, with no replacement planned in the near future.  In all, that gives the Speed family racquets:

IG YouTek Speed MP (18x20):
100 sq. in.
11.1oz unstrung
27in
20mm beam
11pts head light
18x20 string pattern

IG YouTek Speed MP (16x19):
100 sq. in.
11.1oz unstrung
27.25in
20mm beam
11pts head light
16x19 string pattern

IG YouTek Speed 300:
100 sq. in.
10.6oz unstrung
27in
20mm beam
11pts head light
16x19 string pattern

IG YouTek Speed Elite:
100 sq. in.
10.1oz unstrung
27in
22mm beam
4pts head light
16x19 string pattern

IG YouTek Speed Lite:
102 sq. in.
9.2oz unstrung
27in
24mm beam
Even balance
16x19 string pattern

The Extreme family also gets the Innegra treatment, as well as a new model added.  In addition to the new Innegra treatment, the Extreme features an additional change along the throat area of the frame.  While the previous Extreme models all had the elliptical shaped beam (similar to the Babolat Pure Drive that it was designed after), the new models possess a slightly more triangular cross section.  This beam is similar to a less extreme inverted version of Babolat Aero throat beam, but the concept remains similar.  By creating less turbulence through the air, the racquet head can move faster, helping to generate additional spin and power.  The Extreme MP and the Extreme Pro remain in the family, but the addition of a new Extreme OS joins the group.

IG YouTek Extreme Pro:
100 sq. in.
11.1oz unstrung
27in
24/26/23mm beam
11pts head light
16x19 string pattern
 
IG YouTek Extreme MP:
100 sq. in.
10.6oz unstrung
27in
24/26/23mm beam
8pts head light
16x19 string pattern

IG YouTek Extreme OS:
107 sq. in.
9.9oz unstrung
27in
24/26/23mm beam
4pts head light
16x19 string pattern

So who else thought that the surfboard industry would be helping to create better racquets?  It will be interesting to see how well the Innegra fibers hold up under tennis conditions and whether or not the Prestige or Radical lines will be modified.  After a bit of hitting with some of the new Speed models, I can say that overall I like the technology for the comfort and feel, but wish that stability was enhanced more than it was.  The good thing is that at only 11.1oz unstrung for the heaviest model in the line, it still leaves plenty of room for modifications if a player wanted.

Select models are being released in January in time for the Australian Open, with the full line being available in March.