Both the Galaxy S5 Plus and Galaxy S5 4G+ feature the same model name as well - SM-G901F, and have the same specifications, of which the most notable is the 2.5GHz quad-core Qualcomm Snapdragon 805 SoC - a significant bump up from the Galaxy S5 and its Snapdragon 801 processor that also brings integrated LTE-A connectivity. The Galaxy S5 Plus also features 2GB of RAM.
With the Samsung Netherlands listing, there is hope that Samsung is looking to bring the Galaxy S5 Plus or Galaxy S5 4G+ to more markets. Notably, the Samsung Netherlands website doesn't list the Galaxy S5 Plus as available to buy right now.
The Galaxy S5 Plus features a 5.1-inch full-HD (1080x1920) Super AMOLED display instead of the QHD (1440x2560 pixel) display of the Galaxy S5 LTE-A.
Rest of the specifications of the Galaxy S5 Plus are identical to the original Galaxy S5 (Review | Pictures), including the 16-megapixel rear camera; 2-megapixel front camera, and 2800mAh battery. It also runs Android 4.4.4 KitKat out-of-the-box with the company's skin on top. It comes with 16GB inbuilt storage, which is further expandable via microSD card (up to 128GB).
The Samsung Galaxy S5 Plus sports other features from the 2014 flagship, such as fingerprint and heart rate sensors; NFC; USB 3.0 and an IR sensor blaster. The smartphone is water and dust resistant with IP67 certification. It also comes preloaded with features such as Ultra Power Saving Mode, Kids Mode, S Health, and Private Mode.