I've spent 120 hours on overnight trains. Booking a private cabin is always worth the extra cost — whether it's $200 or $1,000.

• On overnight trains, splurging for a private space is worth the price.
• I've slept in private and shared cabins on sleeper trains. In shared spaces, I hardly sleep.
• In private cabins, travelers get a bed, a sink, a vanity, and sometimes a full bathroom.

If you want to sleep on an overnight train, book a private cabin.

Trust me. I've been on six, including two 30-hour Amtrak rides and three 12-hour night trains between European countries ranging from $200 to $1,000. The other ride cost $9,000, but it was on a luxury train.

On four of these journeys, I slept in private, enclosed accommodations alone. And for the other two, I booked shared rooms with up to six other travelers.

I've found that splurging for a private cabin is always worth the price for a comfortable experience.

Some shared sleeper accommodations don't come with a bed

My worst experience on an overnight train was when I booked the wrong room for a 12-hour ride from Berlin to Vienna, Austria.

The ride was operated by OBB Nightjet, and for $40, I booked a seat in an enclosed space with five other people. The seat reclined, but it didn't lay flat. And there wasn't enough legroom to stretch out. I didn't sleep at all on that train, and I got to my destination feeling completely depleted.

"We recommend the sleeper or couchette car for night travel. There is enough space to stretch out," an OBB Nightjet representative wrote in a statement to Insider. "Seated carriages are recommended for shorter journeys."

And I agree.

Private cabins offer peace, quiet, and personal space

For another Nightjet ride, I spent 11 hours traveling from Vienna to Venice, Italy. I booked a bunk in a shared cabin with three strangers for $84. The bunks took up most of the room, so there was nowhere to stand or stretch out. Plus, I woke up several times when the other passengers got up to use the bathroom or to get off at an earlier stop.

But when I've booked private cabins on Amtrak and Nightjet, ranging from $200 to $1,000, I've slept better with no disruptions. And I've had more room to stretch out.

Private cabins have a sink and vanity, and some have a full bathroom

Every private train cabin I've booked has had a vanity with a wash basin, and most of them had toiletry storage, too.

This is a great amenity because you don't have to go to the shared bathroom in the car to wash up. For me, that means I can take my time brushing my trash, flossing, and washing my face. Ultimately, personal washbasins make me feel more at home on a train.

On one overnight Amtrak train from Miami to NYC, I splurged for a bedroom accommodation. For $1,000, I got a sink, vanity, and a full bathroom with a toilet and shower.

I didn't use the shower, but having a toilet in my room meant I didn't have to leave my cabin in the middle of the night.

Private cabins have more space to store luggage

I often travel with just a backpack, but if you're bringing a suitcase, you might have a hard time storing it in a shared cabin.

In my experience, shared cabins have limited storage space. When sharing a room with up to six people, packing everyone's stuff inside can be tricky.

When I was on the overnight train in a seating carriage, people came in and out throughout the night, reaching over other passengers to store and collect their luggage from the overhead shelf.

So I recommend private cabins to all travelers with rolling luggage, a nighttime routine, or a desire to sleep well.