Whenever someone tells me their iOS beta is "too slow," I usually ask one thing first: are you treating TestFlight as your only channel? Nine times out of ten, that's where the problem lives.
TestFlight is fine. It just isn't the "install on demand" magic a lot of people assume. A few limits you can't get around: internal testing groups cap at 100 testers; external testing goes through Beta App Review — a few hours on a good day, a day or two over a busy weekend; every build expires after 90 days, so you re-upload and re-invite; and external testers have to accept an email invitation with their Apple ID. That's a real chain.
None of this matters at the "fifty colleagues taking a look" stage. It starts to bite when your beta fluctuates — a few customers today, a roomful of partners tomorrow. Running every change through review isn't realistic, and wrangling UDIDs and invitation emails gets old fast.
That's why I keep telling teams to hold onto a self-hosted download page. It doesn't replace TestFlight; it covers the part TestFlight is bad at. Host an ad-hoc .ipa on an HTTPS page with an itms-services link and testers install by scanning a code. Or use an enterprise certificate for wider reach. No review wait. Swap the package without changing the link. And you can log who installed which version.
I'm not telling you to skip TestFlight — for public, external beta it's still the least-painful compliant path. Just don't make it the only door. For the scenarios that iterate fast, pull people in temporarily, or can't afford to wait on Apple every time, keep a download page you control. The whole beta flow gets noticeably smoother.