Hi, Steve.
We can't really evaluate your situation because "so big" doesn't tell us the size of your file. :>( You also didn't mention your Windows version or your hardware configuration. Our answer might be different for a PIII with
20 GB HD running Win98, versus an AMD 64 with 300 GB HD running WinXP Pro SP2. Win9x/ME used a memory-management system that caused some problems for Quicken.
But this topic comes up here quite often. Then we old-timers post how long we've used Quicken (15 years for me) and the size of our current QDATA.* fileset (mine total over 29 MB now) and assure the poster that the size of the database is no hindrance to Quicken. Other posters mentioned the .qph file; mine is nearly 3 MB. (My computer is an AMD Athlon 64 3200+ with 1 GB RAM and lots of HD space running WinXP Pro SP2.) Quicken seems even faster for me now than in earlier versions - MUCH faster than in Win9x days, of course! No matter how many other programs are running at the same time.
As the others said, you NEED quick and easy access to cost/basis information on any property (stocks, other investments, your home...) that you still hold and may sell in the future. In my experience, it's much easier to work around a lot of stale data than it is to find old-but-still-relevant data when you need it some day. Also, I find it very comforting to know that my check registers are at my fingertips and I can quickly and easily look up when I bought my old TV set back in the 1990s - and where and what I paid for it.
If you will check the archives of this newsgroup, you will find many discussions of this subject. The consensus, I'm confident, is that a large (however defined) current fileset with your entire history instantly accessible is much preferred to many small filesets with only a year or so in each one. We don't have to find, open and look into the 1996 file; nope, not there, how about 1995?; nope, maybe 1997 or 1998...?
Of course, if your Windows is out of date or your hardware is limited, then the answer might be different in your case. It also might explain the "slowness" of Quicken for you.
RC