Gmail might have been best of breed in 2004 on the basis of its superior spam filter, but that's certainly not the case now. In fact, with the recent change to the UI, Gmail now loads incredibly slowly or not at all on Firefox. It's bad in Chrome too, but much closer to unusable on FF.

No other webmail service I've ever used has given me the lag issues Gmail has.

because fastmail is better than the free one. Just as good in the common use cases, they don't make me the product, and when in the rare case where I have a tech issue their support is responsive. There are a couple other paid email providers that I'm told provide services that are good.