Metal guys like the Maxon for that purpose.
Both boxes have the same amount of gain, but the Maxon sounds more dirty and compressed.
The Ibanez can be true bypassed with some difficulty, the Maxon is almost impossible.
The Maxon OD808 is more or less a TS-10, although it could also be argued that it's something of its own, since they swapped the output resistors around compared to the 10. To my ears, it is a little raspier/rawer than the TS-808, but it should be said that these differences are quite subtle. I assume both would work well for the purpose you're after (cutting some of the bass and pushing the midrange in front of the amp to make it cut a little more).
As for true bypassing, I'd say both are relatively simple. The Maxon is a little more delicate, while the Ibanez has plenty of room for a 3PDT but require slightly more work to modify. Usually, though, when people stick these in front of dirty amps, they tend to be the only pedal. In that case, having the buffered bypass will be beneficial.
I'll go out on a limb here and say consider the TC Spark as well. I have only had the opportunity of playing with a Deliverance a few times. But knowing how the TC Spark reacts against my amps, it would be one of my first choices most likely if I had a VHT Deliverance to use at a gig. I can't say I have tried that combination, but I'm going with my gut.
Of the two you stated though, you won't go wrong with either the Maxon or the TS. I have both and they sing on the 6505+.