At what age are you planning on retiring and how many years from today is that? I think that's the big question and then during those early retirement years, what funds are you going to be tapping? If you defer your pension and your wife doesn't start collecting a pension then during those years are you going to be tapping your TSP (Roth TSP or regular TSP)? Or will you be using your post-tax investments or savings? I believe you can roll your Roth TSP into a Roth IRA, right? I also believe that the Roth TSP is subject to RMD's so rolling into a Roth IRA is probably preferable. During those gap years where you are not collecting a pension, I would at least move some of your TSP (non-Roth) into an IRA in Vanguard/Fidelity and slowly start converting it to your Roth IRA so you are paying taxes at the lowest income level (when you are not collecting pensions) if you are both retired. If you convert from your taxable TSP (first rolled into a regular IRA and then into a Roth IRA) to Roth IRA during those years that you have no other income then you'll be taxed much lower than when you are working or when you are collecting your pension.
I put everything into my TSP right now, maxing it out each year since I started in the gov't, then I do a Roth IRA separately, my wife also maxes out her 401k and we plan to start maxing out her Roth IRA now until at least a decade from now. I still have at least 13 more years in the gov't (hopefully) at which point I'll be 50 and have 22 years worth of service. At that point if I decide to retire and take deferred pension then (if my wife were retired as well) we'd have 10-20 years where I could take a lot of money from my TSP and her 401k, roll it into an IRA and then slowly convert a chuck each year at the lower tax rate to a Roth IRA. Once I start collecting a pension at 57 or 58 or whenever it is, that's taxable income so would be a bit less I could convert each year. So really focus on the years you'll be earning the least amount and that's when you should convert from taxable to Roth IRA.
I think the TSP rules will change eventually where you can take multiple withdrawls, maybe not w/this bill but eventually. The TSP is great in terms of it's low fees but it is basically a legacy fund that is so low b/c it has limited options, it's very basic and that will change as time goes on, especially when more and more FERS employees will retire which is starting to happen and will snowball over the next decade, so the laws will change. With that change though and the military pension changing (and probably Civilians as well) more and more money will be flooding into the TSP, which means changes will happen but it also means with those changes that the fees will get higher. My Roth IRA and post-tax investments are in Fidelity, in low cost S&P and Total Market funds which I think are like 0.045%, so VERY low. Not as low as TSP but almost, so you have options that compare to the TSP and their fees.
I enjoy my job now, and don't see myself retiring until I'm 58 (at which point I'll have 30 years in), but things change, you have new managers and that can sour your job, but even if I retire as early as 50, I'll have at least a decade or two where I won't want to tap my Roth IRA or TSP and will try to live off of my post-tax investments, and during those years I will at least take a big chunk of my TSP/401k and slowly convert it to Roth IRA money so I'm paying less in taxes.
I imagine a lot of the MMMers who are in the TSP program and who will retire early will be in the same boat. If they've been maxing out TSP for decades then they'll eventually have the problem where they may have so much money that their retirement tax rate is higher than their tax rate during the working years. A nice problem to have and people will really have to plan strategically for when they will take retirement money out or convert it so they are paying the lowest possible tax rates.