Instead of getting a 4 ball roller for Christmas, I got this: 

https://www.buddiesproshop.com/shop/kr-apex-3-ball-roller-6142/

KR apex 3 ball roller with 4 5" wheels....

I must say, it's a real good looking bag. Very stable being upright with and without an add-on single bag. Compartments fits everything I carry with its 2 large side pockets and 2 smaller side pockets. Having a storm accessory bag, I always had issues fitting this bag in side pockets of other bags. Not with this bag, I'm able to fit my accessory bag.

Nice feel with the retractable handle and side handles for lift and carry. Very smooth and silent run.....

The color is real nice and the zippers run smooth. though, I wish the zipper handles were a little bigger in size. Overall, first impressions are favorable 4.5 out of 5. Real nice gift. (.5 off just cause it can be heavy lol)

I got the hammer 4 ball roller for Xmas. Santa read my Xmas list. Having my first 4 ball roller, I can definitely appreciate the 3 ball you got. The main issues with a 4 ball are:
- Bottom zippers stick on the plastic in the middle
- No matter how much bag space you've got, it's too $%^& narrow and small.
- It's more difficult to put in the car.
BUT
-No more back problems because I'm only lifting 2 balls. On a previously tweaked and bad back, that's pretty much the holy grail.

Enjoy the 3 as long as you can. they have a lot of value...

I got a used Storm Rolling Thunder 4 ball for Christmas.

I just love the thing. It rolls so smooth. Unbelievable the difference to our other bags in the house.

The Thunder has way more space. The shoe pocket fits my size 13s with room to spare.

I just wished the zipper tabs were a bit larger. My storm accessory bag has bigger and thicker well built zipper tabs.

Wow it's like a dualie truck but a bowling bag!!!!! So dope.

My rolling thunder flips over. Seriously!!!

I'll be looking into this!

I know it's new, but the wheels on the bag hums like a tiny whisper across the unkept parking lot. My other bags sound like the UPS truck is coming. Being Upright it's very stable even with the add on bag. The shoe compartment is actually very roomy, the zippers run smooth. Though I wish the zipper tabs were larger. But zipper pull add ons are just $6 (x10) on amazon. The best part, in the back of my truck, the wheels grip to the surface making it difficult to slide. Great when driving and stopping but it's a pain pushing the bag deeper into the truck bed.  I'm really liking this bag very much!