Quote from Delandel »Looking over people's lists and comments it seems for ramp lots of people are running mana dorks like Arbor Elf while staying away from non-creature sources of ramp like Harvest Season, with the exception of Druids' Repository since it works well with land stax cards like Winter Orb.
What about the Explore Dorks like Elvish Pioneer, Sakura-Tribe Scout, and Skyshroud Ranger? We have low land counts so they can't immediately give us value like a Llanowar Elves always can, but once we start drawing cards we always have extra lands to drop, and when we don't they are still creatures to attack with (assuming someone is open). Are they still good or have people moved away from them?
Edric pretty much relies on having weenies to swing in with, either with Overrun-like effects or by chaining turns, so mana dorks eventually become potential damage dealers as well, where spell based ramp only provides mana sources. Running low costed creature based ramp is just more favorable in this kind of deck.
Winter Orb will limit what Explore Dorks can do, since you are limited on what you can untap. Though to be honest I felt Orb limited me a fair bit and without Reliquary Tower it made chaining turns a bit more challenging, so I dropped Orb from my list. Furthermore, these dorks do rely on you having a land in hand. Most Edric lists will run Exploration already and when you get multiple effects like this it just does less. Sure, being able to churn out lands has a great upside, but regular mana dorks are just a tad bit more consistent in what they do.
The Ranger is probably not too bad, but Pioneer only has an ETB trigger and thus you can end up playing him without getting anything out of it, making it somewhat worse than a mana dork if you can't bounce him. Sakura-Tribe Scout just has less relevant subtypes, not being an elf or rogue is something to take in account as well.