This is the best option for most uses. Probably the only downside of a laptop is its weight when you move around a lot, but there are no perfect devices. You always sacrifice something to get something else.
You know what's cool? Tablets. They're like the perfect mix of smartphones and computers. They have a big enough screen and good resolution to make using them comfortable, but they're still portable so you can take 'em anywhere. Plus, you can get online whenever, wherever. And the battery life is way better than a laptop.
Tablet with a desktop mode feature will be much better, so the experience will be similar as using laptop or pc. Of course this kind of tablet costs more money than normal entry level tablet, but if the main purpose is about to play anywhere, mobile phone is more than enough because currently most mobile phone has big enough screen. I myself mostly gamble at home, so I use my laptop/pc most of the time. I will not gamble in public place although it is easy to gamble with phone, but the main problem is that it is dangerous to gamble in public places since gambling is illegal activity in my country.