Not really.
Two different sizes would be better though. If you can, use a short one so it is harder to get a prying tool/device in there.

Make sure you buy one with a quality key system. If you order from certain online stores, you can have multiple kryptos keyed alike (one key works both, or three, etc....)

Kryptonite locks are currently using a 'rotating disk tumbler' cylinder.
Very hard to pick (like thieves pick though), and there is no spring tension on the tumblers, so they tend to last a long time.

The best KEY SYSTEM on bike locks that I have seen is the 'MEDECO' padlocks that I mentioned before. These are miles ahead of anything else as far as key control and protection of the cylinder itself.

I do not work for medeco. I am not shilling. I don't really care what kind of lock you use. I am only recommending what I have seen and consider to be the toughest, most reliable PADLOCK.

The toughest, most reliable U lock would be the kryptonite brand.

It would be AWESOME if krypto and multi lock would get together and put the restricted medeco key into a heavy duty krypto U lock........