If I understand soaker hoses correctly, they will have much larger holes for bubble release than a diffuser would. The smaller the bubbles being released (for a given volume of air), the more efficient the aeration is. But your "less efficient" system may still be giving you adequate aeration.
You can always retrofit a better diffuser in the future if your interest and budget agree on it. Aeration needs for a new pond are usually lower than for older ones because they have not had as much organic sediment built up to decay and use up O2.