I have traded with probably about 10 different brokers over the past 8 years or so. I think it comes down to what you're looking for in a broker.
Generally speaking, one of the most important things for me has been spreads. In my early days, this wasn't as big of an issue because maybe the broker offered something else that I was willing to sacrifice paying a bit more in spread for. I have now realized that commissions can add up in a real way. Many times have had months were my performance was just mediocre and then I find out I've paid more in commission than I have made in profit. Obviously this is even worse in losing months.
There is other stuff that is really important. A broker should be regulated and offer some kind of an insurance scheme. It doesn't happen often, but I've seen brokers going broke and in this case insurance comes in really handy.
Another thing to keep in mind. Just because a broker shows a low spread or is known to offer good commission, that is not always the case across the board. I have an account with IB for example, which among the lowest, if not the lowest, cost for trading stocks. Seemed like a great idea to open an account with them. Well, I mostly trade currency and I'm getting killed on the commission for that (you have to trade really large size in FX to make it worthwhile). Futures is ok with them cost wise.
I also have an account with Darwinex. I'm happy with them overall. The cost is very competitive across the board. Their customer service is excellent. But most importantly, they are licensed to handle investments. So if down the road you want to have people invest in your account, they can handle that part. This is not the same as copy trading. I wrote a blog post about my experience with Darwinex. You can have a look here - https://www.thegoldanalyst.com/gold/featured/trading-experience-darwinex/398/
I think they are a good broker. But of course each broker has its positives and negatives that is inevitable. As I mentioned it all comes down to your objectives and what you're looking for in a broker. If you plan to trade on your phone for example, some brokers have a much better app than others. Some don't even have one. If you don't have a good charting platform, some are really good. I've traded with Dukascopy before and, in my opinion, their charting platform is amazing. Very much underrated if you ask me.
If you don't stay humble, the market will make you humble