As a general rule, more duration = bigger loss when interest rates rise. The loss is roughly the duration of the bond, in percentage terms, for each 1% that interest rates rise. So 6.5y duration would lose about 6.5% if interest rates rose 1%. With that risk profile, I'm not sure what the benefit is anymore.
That said, I am an inflation skeptic.
Take a look at how rates have behaved over the past 18 months or so. Believe it or not, despite all the financial press headlines about imminent rising rates, our current interest rates are LOWER than they were in January 2020, before the pandemic. I could make equally valid cases that we are (1) reverting to the pre-pandemic norms which are sill extremely low, or (2) returning to a long-term disinflationary trend of falling interest rates.
https://www.treasury.gov/resource-center/data-chart-center/interest-rates/pages/TextView.aspx?data=yieldYear&year=2020Also, watch the Personal Savings Rate. It seems mustachianism has caught on with the masses, because we are currently sitting on a savings rate of 13.6% (last read in Feb, '21)! That translates into continued demand for treasuries from the banks and money market funds holding all those deposits. More importantly, it means that monetary velocity is slowing, not speeding up, despite all the stimulus and QE. Tightwad consumers = less pricing power for sellers and employees = lower inflation.
https://fred.stlouisfed.org/series/PSAVERTFinally, a caveat about TIPS: TIPS are vulnerable to a rare scenario where interest rates rise faster than inflation. This could occur if the Fed jumps the shark in 2022-2023 like they did in 2016-2018 and raises rates prematurely while inflation is still bouncing around the low range. Your TIPS would lose value due to the rise in interest rates and not get much of an adjustment for inflation in return. I can also imagine a scenario where higher rates overseas cause the value of the dollar to drop and the Fed, under political pressure, raises rates to protect the dollar before inflation even starts showing up in the stats that count for TIPS.