Oh, I don't know. I bought the 1.35 volt when it was on sale and recommended to me by MacMan. I bought it a long time ago. The good news is that it's on the Memory List as is the 1.5 volt version. (IIRC, the 1.35 volt version has more headroom for memory OC'ing, but I'm guessing.) As far as I can tell, either the 1.35 or 1.5 will work. Both of the Tactical (1.35 & 1.5) are on the Gigabyte Memory Support List.
To play it safe, your memory should be on both lists. But, the most critical list, IMO, is Gigabyte's.
No, as per my answer to el.Charlot above. I'd go for the less expensive version.
Go for it!
BTW, today, I decided to an old set of Crucial Vengeance Low Profile White 1.35 Volt (2x4GB) as I noticed that it, too, is on the Gigabyte H97N Memory Support List. So far, so good.
Amazon:
http://www.amazon.com/dp/B005DKZK84/
Newegg:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233199