I do, just sold a corrosion golden rune today.

Even if by some miracle tai/nin *ion starts having some sort of visible effect i would not recommend investing on them.

Currently we have 7 spots for 8 gates runes. 5 Should be occupied by Water, Fire, Wind, Earth and Lightning. That leaves 2 spots

Move 1 and 2 should also have quick runes so that's 2 spot less for 2 ninjas. (Some people actually gp for 4 quick runes so that would leave you with even less spots)

It leaves you with the rest of the runes which consist on Explosion (critical), Gale (combo), Inferno (injury), Sand (Damage reduction) Wood (Life recovery), Ice (Control).

Personally I would go with Explosion to your DPS over tai/nin *ion. Assuming you have 2 damage dealers at least in the lineup that's 2 more rune spots that have been taken by those chakras. It leaves 4.

Now of those 4 spots left you have the choice of 4 somewhat useful runes which are Ice, Gale and Sand. Sand does increase defense in a much more visible way than Inferno runes and have a larger effect than wood runes (although a red wood rune can heal you over 200+ additional hp every turn which starts to become interesting). Otherwise you c*e Gale runes to increase the probability of starting a combo which can be useful as wellm or Ice to be sure your control works although it's rare that control fails in pvp.

Basically, unless tai/nin *ion or injury not only start working as intended, but also show a BIG effect on ninjas they are utterly useless. Specially in 8 gates where you have to make choices on which stats to boost. Just sell them to get more runed and hopefully work yourself to a good red one.

The sand runes were reported (old thread from the other fourm, too lazy to find it) to participate in lowering damage to an equivalent of 1/3 to 1/4 of their damage reduction value if it were converted to an increase in defense or resistance.

In other words, a 120 damage reduction would be equivalent to a 40-30 increase in either defense or resistance. Plus this increase will not stack on attacks that are both taijutsu and ninjutsu. When you compare the value of sand runes against wind or earth counterparts the increase in defensive stats is lower by a non negligible margin. A lvl 8 gold Sand rune reduces damage by 674, equivalent to an earth or wind rune of value 225-170. But a gold earth/wind rune gives you a boost of 240 to either resistance or defense.

In other words, sand runes complement nicely defensive runes such as wind or earth, but it's still better to have both earth and wind than just sand.

I personally rate Sand runes below the 5 elemental ones (wind, water, earth, fire, lightnig) on par with explosion runes (crit). The below would go ice, gale and wood with finally Scorch, Inferno and Corrosion being the worst of the lot.