It depends on your luck with getting a soul stealer enchant, It took me about 10-12 before I got a single soul stealer IV sword.
By that time I was about 150 kills away from my T5 pigzombie shard.
So nerfing everything in the name of "balance?" Let's take a closer look:
Changing the EXP costs of uncrafting/repairing or setting it so soul stealer wont work on another sword type would just mean repairing the vile sword more often (assuming the same thing happens with Thaumcraft's repair), which in turn simply means more grinding to achieve the same result.
Aside from a vanilla gimmick, repairing a tool costs more each time (both anvil and uncrafting table), and thanks to another vanilla gimmick you can only go so far on an anvil. The uncrafting table eventually limits itself, as some point its easier to build a new sword.
(Basically makes the game tedious, brings up a lot of AFK time- and as the processes can still be automated, so in the long run nothings changed).
Lower spawn rate of shards, fewer drops/less exp ect.
This makes little difference, its just adds tedium early on- and leaving it running for longer will achieve the same result.
(The forgecraft build has this- no more rare drops)
I have nothing against rebalancing, a long as the rebalance keeps the game interesting.
Simply nerfing something changes little, it just takes longer to achieve the same result.
A rebalance would probably involve making corrupt ingots a more involved process, or some kind of dark magic/corruption mechanic applied to an existing sword which then give it a 'soul stealing' ability.
I've also heard rumours that the soul shards may require recharging after a while, though I'm not sure how the actual numbers would work out.
