Yes, paid proxies can be exceptionally stable and they're usually faster than the free ones. They are vastly superior to the free ones when they work. Looking at the failure modes, however:
You forget to pay your invoice or your card expires and they turn off your access. You're stuck offline until you notice and find and fix the problem.
The free ones just continue on if one gets turned off. Lose one and the bot notices it's disconnected, it exits where the Director restarts it with another free proxy.
Your home IP address changes and the proxy provider decides to not let the new IP address in. This happens more for some people than for others, some go YEARS without a change, some go days.
The free ones just continue on if your IP address changes.
Evony decides they're going to block all IPs whose reverse DNS resolves to proxy-XXX.proxyprovider.com
The free ones don't resolve backwards to something with "proxy" in it or "proxyprovider" so they cannot be blocked en masse. They're also not in a block of IP addresses, they're scattered throughout the world one at a time. If one gets blocked, the bot gets disconnected, notices it's disconnected and exits. The Director launches it with a new proxy.
Your proxy provider gets hacked and forces password resets. It happens, and has happened to someone in the forum and Skype room already.
The free ones don't require a password.
NEW: You have 5 or 10 profiles per proxy that you've paid for. Evony lowers the limit to 3 per IP.
Well, once you notice that you have a bunch of accounts offline, you can go buy some more IP addresses. With the proxylist instead of dedicated proxies, you only have one bot per IP address.
NEW: Some proxies have bandwidth limits. The bot EATS bandwidth. If you notice that the bots start giving access denied errors or other weird errors in the middle of the month, it could be a bandwidth limit.
SSL Private Proxies does NOT have a bandwidth limit. Watch which proxy provider you use if you want to use paid proxies. Some do have limits. It'd suck to be out an entire day (or more) until you notice that you've hit the wall with your proxy provider. You can probably pay them more to get more bandwidth, but you have to hit the wall and be out of commission until you notice you have to pay more.
The free lists have their own problems:
You don't know who is running them, sometimes they don't even know themselves.
It's exceptionally unlikely someone is fishing (not phishing, that's something different) for Evony passwords; if it is really a bad guy running it, he's likely looking for bank or credit card info. This is so very highly unlikely but make sure you don't use a username/password for Evony that can be tied to anything else. If it gets compromised, you can reset your Evony password simply enough. If you lose an alt permanently, so be it.
They die randomly
Yep. They die, the bot notices and exits, the Director launches with a new one.
All in all, the paid ones are superior but they have failure modes that can knock you offline until you notice and correct the problem. The free ones don't. You have to update the free ones on a semi-regular basis. If you have 20 alts regardless of server limits, even a limit of 3, you can get by with 6 good proxies. Keep a list of 100. They're free. At the end of a week, half of them may be dead. So? You still have 50 good ones. That's way more than enough. Thats way more than enough to run 150 alts.
All of that said, I'll throw some confusion out because I'm feeling ornery. There's acually a few different flavors.
- Paid, dedicated proxies. This is what most people refer to when they say they are buying a proxy. You get one or more proxies from the proxy vendor and put them in. You have to manually pick X number of profiles per proxy they give you, then put the info into the profile details page of the Director.
- Free lists. These are exceptionally easy to find and use. There are some lists that are easier to use than others. Some lists are available in the exact format you need with IP address and port specified separated by a colon, e.g. 111.222.333.444:8118, while others require copy-n-paste. Either one works, one is easier to do is the only difference. Most of the free proxy lists will give you literally thousands of proxies.
- Paid lists. These are also easy to find with the added benefit that they are typically tested by the list provider more regularly. Usually, when you get the list, they have a higher percentage that are still working. They also usually come in the format you need without having to do anything further to it so they don't even require the copy-n-paste that some of the free lists do.
Options 2 and 3 are the ones I evangelize because they don't have the failure modes. The only failure mode they really have is that every single proxy in the list could die. Well, if you let that happen, you kind of deserve it. It'd take months of neglect for a list of 100 to die completely. Perhaps even longer since some proxies stay up for years.