---- Toshiba Encore WT8/VT484,
445g, 2-cell 20Whr, GPS (BCM4752 GNSS chips), HDMI-out yes, z3740.
---- Acer Iconia W4-820,
430g, 2-cell 18Whr, Lacking GPS, HDMI-out yes, z3740.
---- Dell Venue 8 Pro,
395g, no list/Dell US, 2-cell 18Whr/info added by Dell UK, Lacking GPS, Lacking HDMI-out, z3740d (cheaper).
---- Lenovo MiiX II 8,
350g, 1-cell/Japanese page/Nov 26, 17.5Whr/Chinese page/Dec 2, (Powermark tested 6 hours 38 minutes), GPS yes, Lacking HDMI-out, z3740.
Acer W4-820 is yet no sales, the spec is based Acer's current Japanese webpage, if finally Acer W4-820 is the sales version no GPS to be unluckily.
Having better portability the 8-inch slates would more likely be using for outdoors and travel purpose, well then, the GPS and HDMI-out are more necessary, it is basic requirements for US $399 to buy this slate (64GB).
Toshiba Encore WT8 (64GB)/VT484 provides GPS and HDMI-out, the battery is 20Wh, claiming the battery life up to 14.1 hrs, or 10 hrs User scenario (65% Web / 10% Video Playback / 25% Standby), or 11 hrs by The JEITA Battery Run Time Measurement Method.
Seemingly Toshiba Encore WT8/Vt484 is slight heavier 90g than Lenovo MiiX II 8", that is actually with slightly larger battery as well as metal parts, better stuff.