Rama

He's a crit buster boi. imo, he's better than Brave Eli because of incoming Dick Wizard.

For critical damage, thus far only Lancelot can be compared with Rama as sabers.
If you have good support to either buff Rama's critical damage, or provide stars (instinct, innocent monster, 2030, etc), Rama's damage is a beast.

Liz? She is good as NP damage, somehow better survivability. But not top class for damaging as Rama.

Saber Eli does better NP damage because NP5 and buster up skill. Rama has better skills overall IMO, with guts, charisma, and an immense crit star/damage up.

So yeah, Rama is very good and has a bit of team support along with dealing overwhelming critical hits.

Simple, Rama is a beast and with the right supp he can unleash massive Buster Crit damage.
He's worth the Investment, can survive in a harder fight and can OHKO enemy within a few turn.
Overall performance, Rama totally bested Dragon Idol Saber.

Maybe you don't get Jalter, but gacha simply give you one of best burst saber. Consider that as blessing for you.
Both also is a broken Buster Crit servant.

Totally depends on which sabers you've already got. Without knowing that, we can't really give you accurate advice. Rama isn't bad, but supposing that you've already got Saberlot or something, then Rama probably isn't worth building. He's a bit better than Elly Brave in most situations, but if you already built Elly, and you've got other servants that you're interested in building in the near future, then Rama probably isn't really a priority at the moment.