Yes, but that is also an extremely biased generalization.
But it can't hurt playing vanilla first, so give it a try.
And now, for everyone's enjoyment the 'Why Complete 2009 sucks copypasta'
- All weapons have their accuracy increased 10-20%
- All damage decreased by few percents.
- Weight limit increased by 10kg, maximum being 70kg. In vanilla the Exo-suit enabled up to 80kg!
- Limits NPC's eye sight distance so they can't spot you from beyond ~100 meters. =You see them always first. Said to remove enemies skill to spot you from"unrealistic distances".
- Sound radius of knife and other critical sounds such as falling dead bodies, grass, and footsteps greatly reduced
- Reduced the sound distance of death cries
- Repair Kit - A special item to the game that allows you to repair weapons and armors out in the Zone. Can be purchased or found.
- The bar trader and Screw now sell weapons and armor repair services. (Not all bad)
- Elite Nightvision - Black & white night vision based on the psy_antenna postprocess effect. Replaces the original UV-based blue NV, and lets you see perfectly in the darkness, be there light sources or not.
- The old, “green” night vision has much less noise and blur. NVs don't emit any audio noise anymore (=can't be heard by NPCs/mutants).
- scientific suits with 90% rad protection now feature an anti-rad injection system.
- bandages auto-apply at 10% health.
- enabled a tracer effect for armor-piercing bullets, making them visually distinguishable when use
- allows looting cash from bodies (CS & CoP only)
- You can BRIBE hostile factions to leave you alone.
They advertise Complete as "vanilla experience", as "only bugfixing visual overhaul". In reality they change the gameplay stufftons, usually only making the experience EASIER than vanilla game. Their bug-fixing reputation is also overrated, Complete09 only uses older beta-version of ZRP as its base, and CS & CoP versions tend to add MORE bugs and annoyances.