Keep the mod UA-5, the price has dropped and you will be losing a bunch of money on it (look like the last one went for a little over $300). Not worth it if you ask me unless you plan to stealth exclusively. Besides, what are you gonna do when you get some mics that require phantom powering (like some SD or LD mics)? You'll have to start all over in addition to buying the mics themselves.
I really love these mod UA-5s (I now own two: W+ and T+), they are awesome little units: easy to power, inputs on the front, light and no bullshit (they are perfect for a Lowepro Nova 3AW). I cannot compare them to these new all in one boxes like the mod PMD671 and HD-P2 in terms of sound but they probably are in the same league after the mods. The R09 is great stealth machine from what I have heard, but the unit has issues with the jacks (mini-in only?).