This is a real can of worms.

I don't think there is a definitive answer. All you can do is consider the various factors that create a particular configuration of hardware and software and make a judgement as to whether this meets you needs.

PC's in general are less reliable than Apple Macs. The PC is an open environment and anyone can in theory create software and hardware which is PC compatible. This ia fabulous in one way; almost anything conceivable is probably out there. The bad news is that it is practically impossible to predict the exact build of any particular PC upon which hardware / software will run. The composite system may be unstable due to conficts between installed hardware and software that are potentially unique to that PC! We can look accusingly at Microsoft and suggest that their software is responsible but giving them sole responsibility is a bit unfair. Loading Linux onto a PC platform might improve reliability from a software viewpoint (fewer drivers which are usually more generic will generally be more reliable) but if you have specific hardware requirements you might not find drivers.

The Mac (per Intel) has always been more reliable because it is not a free-for-all; the available hardware configurations are all tightly controlled by Apple and the Operating system and drivers rigoursly tested - you can do this if there are only a small number of options available. This tight control and consequent reliability comes at a cost; Apples cost more that PCs and the breadth of applications is smaller, but it is not coincidence that many "Professional" audio applications are written for the Mac; again the limited breadth of hardware option means that drivers can be optimised and tested to give a high degree of confidence that the platform will not crash at an embarrasing moment.

It is possible to create a totally reliable Intel / Windows configuration by using Apple Techniques - build you own hardware, write your own drivers, test them to destruction and don't load anything else onto the PC. This is unfortunately beyond the scope of most people!

I'm not sure this helps your cause but I hope it explains why it's a tough decision!