It is surprisingly small ... He elaborates the number of lines of changes in the original XT proposal exceed Segwit changes .
This is a fair comparison because most of the XT supporters are now classic supporters insinuating that Segwit is a massive change when they were will to accept (in some regards- loc) a larger change before.
he says that its safer to do segwit then change the MAXBLOCKSIZE define
trud manure, every word, trud manure
In many ways(not all) segwit is indeed safer than simply increasing maxBlockSize. It doesn't involve a contentious hardfork(99% of people support segwit in itself ) , it allows for signature pruning which reduces costs on the network = safer , Fixes most Malleability issues= safer, creates a Linear scaling of sighash operations = safer, allows for safer deployment of softforks in future, Reduces UTXO growth , ect....