The all-plastic side-slider Samsung B5310 CorbyPRO measures 105 x 56.8 x 15.7 mm and weighs 135 grams. That it's a mere 3 millimeters thicker than the original Corby - that seems like quite an engineering feat. However, the QWERTY keyboard does take its toll and the Pro weighs a good 45 grams more than the plain Corby variety.
Just like the S3650, the B5310 is all plastic. It's a different form factor though and the increased weight actually works in its favor. The phone doesn't feel too heavy, it handles well and the weight distribution is just right for a comfortable hold.
The front of the B5310 CorbyPRO makes it a S3650 Corby twin. The rear also looks quite similar. Another feature the Pro shares with the original Corby is the replaceable rear covers. Unfortunately, the Fashion Jackets aren't compatible across the Corby lineup.
The 2.8" resistive touchscreen display takes centerstage on the B5310 front. It has a 240 x 320 pixel resolution, just like most touchscreen feature phones by Samsung (including the original Corby).
Image quality is middling: indoors the screen is quite good; however, we must say we expected better sunlight legibility. The CorbyPRO screen is comparable to the Nokia 5530 XpressMusic. Another downside is the somewhat poor touch sensitivity.
Above the display we find just the secondary video-call camera and the earpiece - there's no ambient light sensor to adjust the display brightness. Below the screen there are three hardware keys - two receiver keys on each side of the Back button. The hardware buttons on the CorbyPRO are exactly the same shape and size as on the original Corby and the Lindy.
The right-hand side of the CorbyPRO hosts the microUSB port (used for charging and computer connections) and two controls - the shutter button and the HOLD key, which is used to lock and unlock the touchscreen. There is enough space between the buttons and their shape is distinct enough for you not to mix them up. The Lock key is nicely raised and has a very pleasing soft press. The microUSB port is covered by a protective lid.
The lanyard eyelet is on the top left side and right next to it is the volume rocker. Also on the left but beneath the battery cover is the hot-swappable microSD card slot, which can accommodate up to 16GB cards. We tried one and it ran just fine.
On the top there is the 3.5mm audio jack while the mouthpiece is at the bottom. Also on the bottom we find a tiny slit for lifting up the battery cover.
The rear features only the camera lens and the loudspeaker grill. Samsung call the back panel a Fashion Jacket, and will offer a number of exchangeable panels for the phone. You can't use the Fashion Jackets made for other models (such as the S3650 Corby).
Removing the back panel reveals the 960 mAh Li-Ion battery. The battery is officially quoted at up to 8 hours of talk time and up to 560 hours of stand-by time. The only thing under the battery is the SIM compartment.
The rounded design works in favor of the CorbyPRO, whether you are talking or typing on the QWERTY keyboard. The weight is right and the phone handles nicely. Quite sensibly, the side-sliding keyboard accounts for most of the weight and allows a steady hand-hold when typing. The slider movement is sharp and even, no wobbles and creaks.
The Samsung B5310 CorbyPRO packs a four-row side-slide QWERTY keyboard, which is surprisingly good never mind the space constraints. The actual keys are set within a frame of very sturdy feeling plastic, which is supposed to sustain and endure the frequent slider action.
Typing on the CorbyPRO is extremely comfortable: the keys are well sized and nicely convex, and have a very distinct press. Numbers are accommodated on the top row instead of using a numpad layout. The top row by the way enjoys plenty of headroom.
The QWERTY keyboard has dedicated shortcuts to web and messaging. The Arrow keys, Backspace, Enter and OK buttons make sure the keyboard can actually be used full-time for navigating the CorbyPRO menus. Overall, the humble midrange CorbyPRO boasts a full keyboard that easily puts to shame some heavyweight business messengers.