I found another great speed spot, maybe you should check it:
its that small area to the left of fushia right before the gate building with the 3 birdman trainers, great for speed training.
You mostly find fearow (+4 speed), the rest is raticate(+4),ratata(+2),spearow (+2) . These amounts are w/ macho brace, assuming everybody uses it.
The only non speed is doduo, which is like 15- 20% encounter rate but if you consider the double amounts you get from raticate and fearow its totally still worth it,