The E5-551 is a big and fairly heavy laptop, measuring 381.6mm x 256mm x 30.3mm (W x D x H) and weighing 2.5kg (versus the Toshiba C50's 2.3kg). While its weight doesn't prevent it from being portable, you're going to be aware of that added weight when slipping it into a backpack.
Its hefty nature has the advantage of making it sturdier. Build quality is good; there's is very little flex in the base, where it depresses slightly when force is applied to the right of the trackpad. There is far more flex in the E5-551's lid, which bends easily when force is applied at the left and right-hand edges.
The lid is rigid and stays still at whatever angle you position it with very little wobble. It can fold back almost 180-degrees, which would allow you to share content with a friend if it wasn't for the display's awful vertical viewing angles.
The E5-551 has a DVD writer which makes it a suitable option for those who watch movies or work in fields that still use optical media. That said, the low price of the many USB-powered DVD drives on the market means that it's no longer essential to purchase laptops with built-in optical drives if such functionality is vital.
Inside of the E5-551 is a 1TB hard disk drive for storing plenty of programs, apps, media, games and other files. Of that, around 840GB is usable out of the box.
Acer has equipped the E5-551 with a massive trackpad that's smooth and registers satisfying clicks from its left and right buttons. The clickpad is very sensitive out of the box, which is fine for desktop use but way too fast when used for controlling a mouse.
Located above the clickpad is a chiclet-style keyboard with decent-sized keys and a number pad on the right-hand side. Its keys have relatively low travel and feel a little mushy to type on, but it's nothing that will stop you from bashing out lengthy documents with a little practice.
There's no light to indicate when the Caps Lock is activated, which is a small annoyance, but overall I found the E5-551 offers a more pleasant typing experience than the Toshiba C50's tightly-packed keyboard layout.
Connectivity and Wi-Fi
In terms of connectivity, ports on the left-hand edge include VGA, LAN, HDMI, one USB 3.0 port and a headphone connector. On the right-hand edge is two USB 2.0 ports, a DVD writer and power connector. Along the front of the E5-551 is a conveniently located SD card reader.
For communication, the E5-551 is disappointingly limited to 802.11b/g/n Wi-Fi, rather than 802.11ac, meaning you'll be limited to last-generation speeds even if you own a faster AC compatible router. There's also a LAN port if you're in close proximity of a wired connection.