Hm, this is an age-old question.
For one, real-time is harder to program. Output, control, everything is easier in a tb game, because it can be done in a single chunk of activity. But if you've made games before, this won't matter as much.
I'd also think about your target audience. If even you, the creator, needs time to think his actions out, are you sure you would be comfortable designing something intended for those who would rather act on reflex or speed?
If you really despise traditional turns, you might look into a more nuanced turn-based system that takes into account initiative, like Starfleet Battles's "impulse system", which tracks a series of actions more complex than just 'alternate between entities'.