I resisted buying a preamp for a long time.
Me too. My Matrix Element X provides pretty good source-switching and volume control (as well as a very good DAC). However, it does not supply the same signal boost (4.5 vrms, XLR out) as my Benchmark LA4 preamp. The Element X does have a 10 dB output boost, and my Benchmarlk AHB2 power amp has an input sensitivity switch. Together, these 2 controls help with gain-matching. For low level listening, here may be a subtle SQ improvement from inserting the LA4 between the DAC and power amp. In my system, for my ears, this alone would not be enough to easily justify the added expense and clutter. But you do get other benefits from it (including an extra set of analog inputs, 2-way 12v trigger, and balance adjustment).