Here's a couple
updates on replacements I've used while converting an old world, if anyone is interested:
Gems: RedPower adds ruby and sapphire gems.
GregTech does too, so I've converted the gems accordingly. However, this does significantly alter game balance: GregTech gems are much rarer and only occur in certain biomes, in fact GregoriusT recommends disabling RedPower gem ore generation when using his mod. Wasn't sure what to replace green sapphire with, so I used vanilla emeralds - but again, this does alter game balance. Might change this later. RedPower and GregTech/vanila/GregTech gem ores for comparison:
Gemstone Tools: RP2's gem tools are similar to diamond, except have 500 uses instead of 1562. So I just converted any existing gem swords/pickaxes/axes/hoes items to their diamond equivalents with 500 uses left. Unfortunately this doesn't replace any future possible gemstone tools. Considering
Gemscraft, looks very nice as a more thorough alternative, adds a handful of new gems and tools with comparable durability to RedPower2, instead of all 500 uses, they are: topaz (550), amethyst (600), sapphire (650), emerald (700), ruby (750).
Tungsten: Replaced with GregTech tungstate ore, close enough.
Nikolite: Immibis'
TubeStuff mod adds a nikolite storage block (and several others). This block is available even if RedPower is not installed. So to avoid holes where nikolite ore generated, I replaced RP2 nikolite with TubeStuff's nikolite storage block. Looks somewhat out of place while mining, but better than nothing.
Sickle: This handy tool for collecting leaves, grass, etc. now has a couple possible alternatives.
For comparison, the RedPower sickle comes in 8 variations, of differing durability. It is a fairly cheap recipe, suitable for early game. Here's the area it covers, when used on leaves (left-click, as if mining):
Extra Utilities 0.1.3 adds a Foliage Axe, crafted with "unstable ingots". Unlike RedPower sickles, it only comes in one variation, and is activated by right-click instead of left-click. But it covers a huge volume:
(ignore the decayed leaves, those are a result of using //set leaves in WorldEdit create this large mass of blocks). Using the axe I was able to clear out all of the leaves shown here very quickly. This is the item I replaced all my sickles with during world conversion.
However, newer versions of Extra Utils removed the Foliage Axe.
Fortunately, as mentioned earlier in this thread and in Direwolf's mod spotlight,
Dartcraft adds a comparable tool, the Force Mitts. I installed this mod mainly for the Force Mitts, though there's plenty of other interesting features added as well. The mitts are crafted with a force ingot, work on leaves, grass, etc., and cover a range between RedPower's sickle and ExtraUtils 0.1.3's foliage axe:
Also they create nifty particle effects when used. Not bad a sickle replacement tool at all.
