Yes, at least in my limited experience. I have my 401K money with Vanguard, personal money with TRP. Vanguard is still well below its pre-08 high point, TRP recovered some time ago. Now some of this may be because I'm limited in the particular Vanguard funds I can invest in (due to prior employer's plan choices), but I don't think a few fractions of a percent difference in expenses is critical.
It's not critical, but it really takes money out of your pocket (used an online calculator here and compared the TRowe 2050 targeted account vs the Vanguard one):
Amount invested : $10,000
Annual return : 7.00%
Projected expense ratio is : 0.17%
What if the expense ratio is : 0.78%
Your investment returns over 30 years will be $11,456 less if the actual expense ratio is 0.61 percentage point(s) more than the projected.
Projected expense ratio
Actual expense ratio
0.17% 0.78%
Net market value after Difference
1 year $10,683 $10,622 ($61)
5 years $13,914 $13,522 ($392)
10 years $19,361 $18,284 ($1,077)
15 years $26,940 $24,723 ($2,217)
20 years $37,486 $33,429 ($4,057)
30 years $72,577 $61,121 ($11,456)
You're out 11.5k for very similar returns. Remember, the returns they show you on their little graph are ignoring the ERs.