It made an enormous difference for me. Over the past 15 years, I've attended TM in three phases: once for a couple years to get through the initial course of about a dozen speaking assignments, and then twice since then for tune-up sessions of about a year each. I started out as a typical engineer who meandered and stammered my way through team meetings, and now I've successfully presented before audiences of several thousand people. I admire top Toastmasters speakers far too much to call myself an expert, but if public speaking were a pass/fail test, I know I'd easily pass.
What makes Toastmasters work is the immensely supportive environment. I've never felt so welcomed anywhere as I have at the weekly TM meeting. They want you to succeed, and you can feel their positive energy just as the butterflies are trying to overwhelm you at the start of a speech. They are experts in delivering constructive criticism while still reinforcing what you already do well. Most important, you'll find that you'll start looking forward to public speaking.
As for the original question about spontaneous interview conversation, TM helps there, too. One part of a usual meeting is "Table Topics," where the host calls on random attendees to get up, stand in front of the the room, and spend one-two minutes answering a simple question like "have you ever owned a pet?" It's high-pressure but low-stakes, and it's great practice for getting comfortable with that common situation of having nothing to say but needing to say it.
I can speak to that directly and Toastmasters helped me a lot. In my club for every speech there was an Ah-counter who counted all the interjections and unnecessary words. In my opinion this feedback, weekly over a long period of time, is the only way to improve on this subconscious utterances.
Besides prepared speeches everyone did short two minute impromptu speeches at every meeting. We always got feedback, verbally in front of the others as well as in writing and secretly. Even the short speeches were strictly timed and Ah-counted.
It's all very simple but done every week for a few months improvement is inevitable.
Membership fees were next to nothing and there was no long term commitment. You could just pay in cash at the meetings. Toastmasters is also a non-profit, so little money but well spent.
The meetings back then were always open to anyone and you could just hop-by without registration or being a member. As a non-member you could even participate in most of the activities but you wouldn't be given speaking slots.
Downsides? You will have to invest a significant amount of time and energy.
This is a good point. I forgot about the fact that I took a “speech” class as a freshman in high school, then again as a freshman at a community college. It helped!
What makes Toastmasters work is the immensely supportive environment. I've never felt so welcomed anywhere as I have at the weekly TM meeting. They want you to succeed, and you can feel their positive energy just as the butterflies are trying to overwhelm you at the start of a speech. They are experts in delivering constructive criticism while still reinforcing what you already do well. Most important, you'll find that you'll start looking forward to public speaking.
As for the original question about spontaneous interview conversation, TM helps there, too. One part of a usual meeting is "Table Topics," where the host calls on random attendees to get up, stand in front of the the room, and spend one-two minutes answering a simple question like "have you ever owned a pet?" It's high-pressure but low-stakes, and it's great practice for getting comfortable with that common situation of having nothing to say but needing to say it.