I just ordered a 6.5-300 Vanguard for $469/shipped & no tax. I can load hot or not so hot, why get something smaller that limits the upper end?
Only you can determine if it makes sense for you. For myself, there are various reasons not to go 6.5-300WBY.
One is brass cost and down-the-road availability. My 6.5-06AI beats the 6.5RPM by 100fps with 140g bullets and fire-formed .25-06 brass, using a 24" barrel. It, too could be easily downloaded. The fire-form loads are very accurate out to 600 yards, with little recoil.
Another is, although I have several light to very light loads for my rifles (.308- and .30-06-level loads for my .300WM and a 300g bullet with a mere 13.5g HS6 in a .45-70 case, for example), as a rule I prefer near case-filling to slightly compressed powder charges. This helps avoid bullet setback and overcharges. Haven't shot the light loads in the ,300WM for years as I now have both .308 and .30-06 rifles. The .45-70 load is still very popular with my girls and myself - less than half the recoil of a .30-30 factory load, very accurate and pretty destructive, even if the range is limited by a .22 Short type trajectory,
A third is I already have rifles that reach as far as I'm willing to shoot at game, and if I was going for long range targets I'd go with a larger diameter and heavier bullet. Maybe a .300PRC or a .338 of some sort.
Barrel life with the full power loads is a concern. I like my rifles to last like the Energizer Bunny. My 7mm RM is still running strong after 37 years.
Lastly, I'm a slow adopter in most cases. A true stick in the mud, a "Show me" Missourian from Iowa. At this time I just don't see the benefit outweighs that offered by the alternatives.
YMMV.