Performance (At same power) is as follows
TSMC 28HPM - 1x
TSMC 20SOC - 1.15x
TSMC 16FF - 1.38x (1.15 x 1.2)
TSMC 16FF+ - 1.59x (1.38 x 1.15)
Area
TSMC 28HPM - 1x
TSMC 20SOC/16FF - .55x (1.9x density increase)
TSMC 16FF+ - 0.4675x (15% denser than 16FF+)
Power (at same performance)
TSMC 28HPM - 1x
TSMC 20SOC - 0.7x (30% power reduction vs 28HPM)
TSMC 16FF - 0.46x (35% reduction vs 20SOC , 54% reduction vs 28HPM)
TSMC 16FF+ - 0.322x (30% power reduction vs 16FF)
http://www.eda.org/edps/edp2013/Papers/4-4 FINAL for Tom Quan.pdf
(page 19)
http://www.tsmc.com/uploadfile/ir/quarterly/2014/1aT1b/E/TSMC 1Q14 transcript.pdf
(PAGE 4)
"Our 16 FinFET plus matches the highest performance among all available 16-nanometer and 14-nanometer technologies in the market today. Compared to our own 20 SoC, 16 FinFET plus offers 40% speed improvement. The design rules of 16 FinFET and 16 FinFET plus are the same; IPs are compatible".
https://www.semiwiki.com/forum/content/3688-samsung-foundry-explained.html
Area
Samsung 28nm (gate first) - 1x
Samsung 14LPE (gate last) - 0.55x
Samsung 14LPP (gate last) - 0.55x
Power
Samsung 28nm (gate first) - 1x
Samsung 14LPE (gate last) - 0.49x
Samsung 14LPP (gate last) - 0.40x
TSMC 16FF+ should beat Samsung 14LPP in performance and power efficiency. Density remains to be seen because Samsung 28nm gate first was more dense than TSMC 28HPM (gate last). But as always these claims have to be taken with a hefty dose of salt. Final products are the real measure of the process' power/performance/area claims. The biggest factor which trumps all these 3 factors is yields. At 14/16 FINFET the fab to win will be the one which can ramp production at good yields.