Here's a good article from AOPA that I've shared before.
Straight-In-Approaches It's worth reading.
In one example, the Alaska Airlines pilot was suspended because he made an un-authorized right-hand pattern. He claimed he turned onto final about 4 miles out, making it a straight-in approach. In this case, the judge said 5-6 miles out for an airline could be considered a straight-in approach, not 4 miles, or the 1-2 miles out they actually found out he turned. All at the judges discretion though, no law says be 5 or 6 miles out. The NTSB backed the judge.
In the second example, the jet making a straight-in approach interfered with a plane doing a practice approach. He was suspended for 20 days. This case applies more to what we're talking about. The NTSB said that even if it was a valid straight-in approach, he would have been in violation because he "
interfered with other aircraft in the standard left-hand traffic pattern". So this time, he was 3.1 miles out when they say he was aligned with the runway. Wouldn't this be 'final'? I think the moral of the story is, if you're doing straight-in approaches, you'd better make sure you're not interfering with someone using the standard pattern.
And yes, when the airport is calm, I use a straight-in approach. I'm pretty careful about it though.