The mana investment for the backside is 4 a turn, which is a real cost. Or it's a plains at some point, probably on t4 at best. Free ramp is nice, but I'm not getting excited about ramp that requires me to attack with three creatures, since that's typically the type of deck that wants ramp the least. We've seen this happen a lot with Gideon/Kytheon where he won't immediately flip at the point where you could have three creatures because of removal or not wanting to alpha in with creatures and lose value/need to hold some amount of mana up, and while this is different in that regard it's still the same in keeping three creatures on the board sometimes being a herculean task in cube. So for a number of turns your W investment will be a 1/1 lifelinker, which feels bad.
But unlike with Kytheon, which heavily rewards you once you flip him since he's a pretty great PWer on the backside, you get a land with an expensive activated ability that makes 1/1s. Sometimes you'll be able to use the extra mana, sometimes you can sac it, sometimes you can invest the 4 mana to get a soldier...but that doesn't really feel great, I don't feel like I'm getting rewarded with that type of return, and if I'm successfully attacking with 3 creatures I most likely want to start closing the game out, not just making 1/1s. It'll be good insurance vs wraths, but even then that requires a specific series of plays to get to that point, and decks with wraths will also be able to stop you from getting 3 attackers enough to make this inconsistent.
The other cards seem a lot more appealing because they go in shells that can really use the mana investment and want to get into long(er) games where you have time to play your spells and then activate the backside. If this is the type of spell that appeals to you for this type of deck, I would look toward
Kjeldoran Outpost first if you're not running it, as I think the cheaper cost of activation and losing a land is a bit more better from an attrition/soldier spew point of view vs a 1/1 and more creatures to flip to pay more for soldiers. I'll be watching testing results from others, but it would have to be across-the-board positivity on the card since in theory it looks really 'meh'.