I have a turbo trainer and a set of rollers.
Turbo trainers are brilliant for hard intervals because you don't have to think about balancing after an 'all out' set. You can switch off on a turbo trainer, watch the telly, take your hands off the bars, have a drink etc. You're static, plugged into it so you're not going to fall over.
It takes a lot of faffing around to set up though. Especially if you need a turbo tyre meaning you either have it mounted permanently on another wheel that you interchange, or actually change the tyres each time. Done that before
Unless of course you have a bike which is always on the turbo. This is what I would like, if only I had an extra bedroom.
I keep the turbo in the greenhouse as it's a bit of a pain to store, because I already have the rollers under the bed.
The rollers are brilliant. Easy to learn, you'll have it cracked in 1 minute, they're no problem. Anyone who can't suss out how to ride rollers needs to take a long hard look at themselves. They are very easy to set up and put away and you don't need to change anything about your bike. Just stick it on and go. No distractions though, you need to pay attention here or you could be on the floor. Just like a normal bike I suppose.
They can be used for resistance training to a point too. Trust me, if you had a reasonably large gear and tyres at about 90psi, you'll break a sweat pretty soon.
You can really feel the pedalling sensation too, the movement afforded on rollers allows you to more accurately judge your pedalling technique and feel where your power is delivered in each revolution. I'm just off my rollers now, had a quick blast for an hour in the kitchen. The turbo doesn't get much of a look in until it's time for hard intervals.
The rollers can fit under the bed for easy storage.
I hope that helps.