Even most tech people think in terms like "do you NEED it?" and "a laptop should do it", etc., when the reality is still as simple as 4.4GHz > 2.5 GHz.
Of course a fast PCI-connected SSD is also very important. All new mainboards have an M.2 slot for this, it's just that most people completely underestimate how much you will feel this speed gain in everyday usage.
Anyways, money was also the main reason I built one. I absolutely don't regret it.
The quintessence is: don't get your teeth too deep into some problems that will arise. Onboard sound doesn't work? Buy a cheap USB-Dongle. iMessages doesn't work. Well, I ended up using iPhone for replying to these and if it's a longer conversation, I'll do it on the MacBook. Bluetooth is unreliable? Try another crappy dongle from Amazon and don't even bother about refunds. Sleep doesn't work? Well, see how little this thing draws in idle and postpone any action for some months.
You might be able to get rid of all the arising issues by fiddling enough, but in the end these are what make the experience unpleasant and the Hackintosh becomes a time-sink.
If you stick to the basics, you get a very fast machine.