Should I rollover my old 401k to IRA or keep it with my old employer? ?

Self-directed Roth IRA.  Then invest it all in an ETF called SPY.  Also make regular monthly buys of SPY in the same dollar amount.  Average annual return since 1977, after taxes and with dividends, is 12.5%.  No other investment in the world can say that.  Every Senator and every Representative retires on SPY investment.

Roll over to IRA. 

A 401(k) has higher fees and very few choices for how to invest. An IRA lets you invest in zero-fee funds or whatever else you want.

The decision between traditional IRA or Roth is equivalent to: will your tax rate be higher this year or during retirement?

That can be a hard question to answer since it requires predicting the future. But if you expect to have a very low income this year, a Roth account would be good.

How old are you?  If you turned 55 before you were laid off, but are not yet 59.5 years of age, leave the 401K with the employer.  In the event you need to take the money from the 401K and meet this age test, no penalty applies.

You should roll it over.

You will no longer be restricted to only the options that your employer has provided you with.

If you want to keep it with the same elections you can (outside the employer's plan), but you will have a choice to roll it anywhere you want.  Also, the fees are usually less for individual IRA than fees for former employees in an employer plan.

In response to N/A = he meets the age test but most employers have restrictions on withdrawals, usually only allowing them once every year. 

No one here knows what types of investments and the fees are of your 401k. 

If you roll over to a self-directed IRA you can decide where to invest it.

Roth IRAs are great, but if you convert to a Roth, that's a taxable event.   It might be a good year to do it if you expect less income.

It depends on how good the investment options are.  You have many more options if you roll it over. Note that if you roll it to a Roth you will have to pay income tax on the amount. If you roll it to a Traditional IRA, it will be tax free.