(JP from Realm here)
Yes, it's all bits, but those bits matter :). The internal query engine is extremely optimized based on the layout of those bits, on a per-architecture basis.
Also, integers are adaptively bit-packed, so you shouldn't worry about the size of your integers, as Realm will intelligently use the appropriate widths.
I'd suggest continuing to use this computed property pattern and to keep track of #651[0] where we're tracking better support for this.