NEW YORK (TheStreet) -- With rumors about a larger iPad coming from Apple (AAPL) - Get Report in the near future, it was interesting to hear Asus announce its own large tablet design earlier this year. After putting the new Transformer Book T300 Chi Ultrabook through its paces, we're wondering whether anyone will use the new model as a full-time tablet rather than as a thin sliver of a laptop.

The T300 tablet portion is very thin, measuring 12.5 by 7.5 by 0.3 inches. Attaching the keyboard half doubles the thickness to 0.6 of an inch. The tablet weighs 1.6 pounds by itself and adding the Bluetooth keyboard cover brings the Transformer's weight to 3.15 pounds. Apple's new MacBook is even thinner (0.52 inch) and lighter (2 pounds) but can't be used as tablet.

Like Microsoft's (MSFT) - Get Report Surface Pro 3, the Asus has almost all its ports on the tablet half, while its detachable keyboard/cover and a micro USB 2.0 port reside on the bottom half. There is also a micro USB 3.0, a micro HDMI and a proprietary AC charging port on the tablet half. Unlike the Surface Pro 3, the Asus has both tablet and keyboard cloaked in a metal frame.

The T300 Chi has a 12.5-inch touchscreen display, a new, low power, Intel (INTC) - Get Report Core M processor (like the new MacBooks), 8 GB of RAM and a 128 GB solid state storage drive. Using the new Intel chip means no fan is needed to cool the inside of the enclosure. The downside is that battery life with the new processor, while very good, is not exemplary. We were able to squeeze approximately 7 hours from a fully charged battery.

The T300 is well built. Fit and finish are terrific. The computer was able to handle all the usual tasks we we threw at it -- Web browsing, word processing, streaming audio, video and TV shows and even some light gaming. The T300's processors along with all that RAM were well up to the task.

But the keyboard is a little cramped for average-sized hands, and the keys are not backlit. Joining the tablet and keyboard pieces together is somewhat tricky and not as smooth or precise as the system built into Microsoft's Surface Pro 3. The keyboard communicates with the tablet via Bluetooth and not via a more solid, wired, plug-in port solution. While we're at it, the trackpad seemed a bit small too.

Lastly, we would have appreciated a full-sized USB port or two for the many add-ons we're used to incorporating. Facing the same predicament, Apple announced that it will offer only one, small, reversible USB 3.1 port on its new MacBook.

All of this adds to our conclusion that not many people will use the tablet alone. That's not because it doesn't work well on its own (it does), but because holding and using a 12.5-inch tablet that weighs more than a pound and a half can be tiring. If you need to hold it for longer than just a few minutes, you may find it necessary to shift your grip or take a break and put it down. It's more likely the Chi will be used with the keyboard attached.

Prices for the T300 start at $699 for models with a "Full HD" display, while the version we tested, with a WQHD (Widescreen Quad High Definition) display, retails for $899. That puts it in the same price range as the Surface Pro 3. Choosing between the two, especially with recent Microsoft discounts, could be tough.

When considered as a modern convertible computer, the Transformer Book T300 Chi could be a good choice as a portable with a large dose of tablet functionality thrown in.

Overall Rating: 8.2/10

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.