Just going off things we know for sure at this moment...
Trees debarked with only stumps of largest limbs remaining is EF3 expected damage, but only can be determined up to the highest (167 mph) at that scale. After that it becomes impossible to tell with any certainty how strong the winds were.
Likewise, we know transmission towers outside of Birmingham were taken down. Again this type of damage is consistent with EF3 damage, but once total loss occurs it is impossible to tell if winds were stronger.
As for other structures we've seen, there was that McDonalds in Tuscaloosa that was rendered down to just about nothing but the guts (could even argue completely gone). This damage is consistent with EF3 (or high EF4 if you consider it a total loss), and again higher wind speeds can't be stated with any certainty because the structure is expected to be gone at high EF4.
Easily EF3+, almost definitely EF4, and I personally need some context with what certain structures were before they were reduced to rubble before declaring EF5 for sure.