Obviously I do not agree with that position. Firstly, I played Xenosaga Episode 1 and 2 before Xenogears. I played Episode 1 shortly after its release here in the States and I didn't play Gears until maybe late 2005.
Now....which do I prefer... It's a bit tough to compare since you are having one game take on three games. However, given this is Xeno, I tend to ignore things like gameplay and graphics and al that. Let's not kid ourselves - we are into Xeno because of the Plot and Characters. Music too. So I don't think it's quite as difficult to compare Saga and Gears on those grounds. Although I guess Saga has three OSTS on its side while Gears only has one. Still, I think Xenogears has possibly the greatest JRPG soundtrack in history so it can take on three other OSTS.
I will make my thoughts on this brief because I really want to read what others have to say.
For the Plot, it's gotta be Xenogears. The fact is that everything just came together so much more smoothly and was a lot more rewarding. The revelation of Deus and everything made sense and explained things very well I thought. Meanwhile, Xenosaga and its painfully vague "Ancient Civilization That Did Everything" annoyed the hell out of me. While it did do tie everything up, and it succeeded with things like Old Miltia in EP3, it did generally disappoint me.
This also plays into Characters I guess but it's still central to the narrative so I'm including it here. I adore Xenogears' love story. The timeless tale of The Contact and Elly was amazing and Xenosaga has nothing like it. Perhaps its' the romantic sap in me but I felt the love story strengthened Xenogears' narrative.
Now....to Characters. Saga blows Gears out of the water. Xenogears has many failings but chief among them is just dropping characters into some Plot Void where you never hear from them again or they never do much of anything again. True, what happened to Billy and Maria is characteristic of many JRPGs I've played (Moment of Awesomeness and Development followed by Irrelevance) but the tragedy of Rico cannot be forgiven. I absolutely hate that his whole story was dropped and we never saw Sigmund again after Nortune. And let's not forget how Ramsus kinda just buggers off to have a fivesome with The Elements or something even though he's the second strongest being alive next to Fei. He could have been a big help against Deus ya know.
I also think the fact Krelian was introduced so late is a big reason why I had trouble giving a crap about him. This is a common complaint in JRPG fandoms. A character entering teh game too late is often just not accepted by the players.
Now Xenosaga, Episode 1 was a fantastic ensemble piece where everyone had their characters well established yet they were all tinged with mystery. You needed to play the other games to find out what would happen to them! To find out about their enigmatic pasts! Then Episode 2 screwed that all up but Episode 3 was nice enough to give us a lot of very nice closure. The URTVs, Ziggy, Jin, Shion, KOS-MOS, everyone except I guess poor MOMo had a place in that game and never felt useless or unnecessary.
In summary, there is no Chu-Chu in Xenosaga. It wins.
So that's me. Now tell me about you and your views.