Dragon Magic presented draconic Lineage feats, which let you convert spell slots into various attacks/abilities that varied in power by the slot spent. Complete Mage gave us Reserve Feats, which gave you an infinite-use spell-like ability as long as you had the ability to cast an appropriate spell, and said ability varied in power by the spell unspent. I can't seem to decide which would be better; on one hand, Draconic Lineage feats let you have a particular type of spell at any level without taking up space on your spell list, but requires Draconic Heritage as a prerequisite. On the other hand, Reserve feat's abilities are unlimited use, but would require you to have a decent stock of the appropriate spell type on your list, which might make you easier to counter. Which should I choose?
In general, Reserve feats
You can hold down a Reserve feat forever and ever as long as you've got an appropriate spell memorized or spell slot open. This makes them great for backups, out-of-combat healing, blasting, and a myriad of other things that you might want to have around but don't really want to burn precious spell slots on. Reserve feats can be a great way to make a character feel more magical without having to optimize your numbers or carry around enough scrolls to found your own library.
A note: Reserve feats don't eat up the spell you need to have memorized in order to use them, which means that you can set that spell slot and forget about it for the rest of your career. Unless something starts ripping into you with negative levels or mental ability score damage, your Reserve feat will always be active and ready to rumble.
I'll cast my vote for reserve feats also, for me they've solved a great issue regarding party balance. Either the party worked at the speed:
- of those with spells i.e fight until there are no more spells then rest thus the classes who theoretically could go on longer lose their advantage(that they fight longer)
- of those without spells and in some fights I have rounds where I have to use my crossbow so that I have spells left over.
This is solved you see by the reserve feat and always having a bit of fire or lighting so I can so we can go with the second option.
And even if we go with the second option another advantage was that in my heart of hearts, I always thought no true wizard should run out of magic, so reserve feats were a great help with this fluff wise in 3.5 .
Part of it depends on your spellcasting class. For most, I find Reserve feats highly useful, and the Draconic Lineage feats suboptimal at best, but its really not a direct comparison, since they give two very different types of benefits, useful in different ways to different characters. The reserve feats are mostly useful for increasing staying power, for characters who find themselves constantly running out of spells/slots while the rest of the group is still good to go. Draconic Lineage feats are more of a versatility boost, useful for spontaneous casters with limited spells known to get additional effects, as a scaling alternative to Extra Spell, or for preparatory casters to have an effect always available spontaneously, such as a researcher who wants to load up on research-aid spells, and still have some combat options if he gets jumped in the library.
For preparatory casters, the Lineage feats are rarely worth it for adventurers, as you can usually get a stronger version of the same effect by learning an appropriate spell, whereas the infinitely reusable nature of the Reserve feats is a big help if you have a group that doesn't habitually rest after every stray goblin. However, from the OP's stated concerns about having to fill up with qualifying spells every spell level to use them, it sounds like he/she is running a spontaneous caster. In that case, it may be worth the reduced power of the spell for a given slot vs Extra Spell in order to have it scale as you level up, and to get that type of utility from every spell slot with a single spell's worth of investment. Conversely, Reserve feats are significantly less attractive to most spontaneous casters because of the aforementioned concern with loading up on qualifying spells every level, and also because they tend to have far more generous spells-per-day progressions to begin with, so they have less to gain from the improved staying power.