I fly a couple of times a month and have found the passport process roughly evens. In some cases the international channel goes quicker than the EU channel and some airports have better international facilities than EU/Domestic - shorter queues etc. But it's never been more than 10-15 mins extra.
The Schengen limit was a pain, but its easy to deal with Greece hands out visa's like sweets and France and Spain want the limit dropped of extended.
UK airports don't exclude EU passports from the domestic channel, because they realised it would create delays and the need for more infrastructure. The UK also allows EU citizens to stay up to 6 months without a visa.