Thanks. I agree the fee for MWTIX is acceptable for a 401k. I really don't like that it's 30-40% mortgage backed securities and stuff like that, but suppose that should be ok. Don't know if that is better or worse than more corporate bonds..? NEZYX does look really wacky, will stay away from that one.
Messed around with my allocation spreadsheet now, and the trouble is my 401k contribution is nearly $30k per year (thanks to a good match), while my taxable contribution is much lower, especially next few years with baby and daycare expenses.. So I'd end up with my taxable almost full of bonds. Now in theory it's all one pot, but I've kept 401k+roth and taxable allocations separate for now. Mainly since I figure they have different timelines (taxable first 5 years of FIRE), not to mention investment options.
I think I'll move some over to MWTIX, and keep bugging HR about better bond funds. And hope for the best (only one mortgage crisis per lifetime right...?)
edit: another thought is to split it. Do 10% in MWTIX, and 10% in muni bonds in taxable. That's not as huge a percent of my taxable in bonds, and should make rebalancing easier, and give some diversification too.