What? You don't need to TSOP flash it, I've installed almost a dozen or so with Chimp on soft mod only.
And when you don't TSOP flash it, you have the chance of going through the same multi-months process of getting it re-modded when XboxHDM doesn't work on <5 year old computer and everything else goes tits up, when literally every thing that could go wrong with it, did.
Dead laser, replace laser. DVD drive dies entirely. Buy second xbox for dvd drive. Same type, but works. Make flash drive adapter. Not a single flash drive or micro/SD card or reader I own works on the xbox. VM won't see memory card adapter to transfer saves to. Eventually get it to work, transfer linux launcher and softmod installer to memcard, then to hard drive. Boots to a black screen or error 21. After trying ~8 different softmod packages. ActionReplay memcards can corrupt large saves. Order official Microsoft memcard. Guy shipped it to someone else on accident, order is cancelled. Try to hotswap hard drive into live Windows environment to read with Xplorer360. Electrocute self on PSU. Erase C drive. Xplorer360 won't write files back. Try different Xplorer360, works fine. Flash TSOP, still won't boot without DVD drive. Fucking around with the settings for ~2 hours, it finally works.
Alternatively, if I had flashed my TSOP the first time I softmodded it, I could have just formatted the hard drive with a Linux liveCD when I ran into a PEBCAK error, loaded my files on, and been done with it. In a few hours.
Ask
DinohScene. He'll vouch for my story, I pestered the ever living hell out of him through the entire ordeal lol.
tl;dr - flash X2 5035, good bios, no reason not to tsop flash, murphy's law, etc