We're currently using HSNM Hotspot Manager which is ok management wise and it ingrates nicely with MikroTik to serve HTML pages and handle logins locally, but there's just too many issues that seemingly cannot be fixed. Such as users having to continually log in (despite having the timeout periods set high), occasional memory leak requiring a server reboot, vouchers being remembered by host devices even when expired hence cannot enter new details unless we manually recharge the old voucher

The good things about it (which we would need in a replacement)
- Centrally manage all our hotels from our primary logins. Access details of any voucher in our entire network. Work with all our hotel domains at once
- Hotel managers have their own login domains and only see information about their own hotel. Generate/recharge/modify their own vouchers etc. Limited access so they can't screw things up
- Basic WYSIWYG web template editor where we can upload information and images of each hotel
- Integrated payment system
- Product plans with policies (different speed limits, number of devices connected etc)
- Ability to set both data and time limits on vouchers
- MAC address hotspot bypass

We don't have web coders so designing web pages for every hotel and trying to piece it together just using Mikrotik's internal User Manager is not a solution. Besides that is not centrally manageable externally. Most of the products i've seen are for individual hotels, not designed for centralized management. At the end of the day it needs to be something that we can just use, not something that turns into a full time job to maintain

What other products are people using? And whats your overall experience and happiness with it?

Unfortunately, mikrotik is not the best platform for hotspot services, having above-basic requirements. One reason is, that RoS is closed, so no special customization possible.
This said, you might take into consideration, that there are a few hotspot+management packages available for openwrt-based devices, which should fulfill your requirements.
Certain mikrotiks can run openwrt, so you might evaluate, whether switching to openwrt is possible for your equipment.

In all honesty I don't care if its MikroTik based or not. Infact having dedicated boxes we can easily spin up and install onsite to take care of that location i'm all in favor of as it moves that component completely off the main onsite router, easing troubleshooting and management
But it must be something that is centrally manageable

Do you have any recommendations?

This is not the right place to make recommendations out of mikrotiks environment.
For openwrt based systems, which includes several mikrotik devices, hotspotsystem.com is a good choice. Or ct-networks.io

I have no connections with both.

This is not the right place to make recommendations out of mikrotiks environment.

...Ofcourse it is, the OP is asking for a radius system that he can use WITH his mikrotik devices. That is a perfectly good question.

OP not asking for radius only. Radius usually is part of any good management system, but only small part.

You definitely need a programmer. He will solve all your problems very quickly.