This was taken from another forum but this pretty much sums it up for me:
"OK, I've been at this on and off over 3 decades and have done, and seen done eq alone, deca alone, eq with test and deca with test. Back in the 80's Deca was all the common users base. The more infomed elite used test as a base from my experience. Anyway. Nearly everyone had ED issues from deca over time but some lied about it.
Equipoise alone: Pretty much a hardener with little weight gain and moderate strength gains. Some loss of libido. On an average bodybuilder alone boldenone will give 6-10 lbs of gain.
Deca alone; Libido killer by the second or third cycle. Long lasting ED problems post cycle. Good strength gains and moderate weight gain. More weight gain than Equipoise at the same dosage. Less notable hardening than Eq. Weight gains look softer. Good strength gains.
Equipoise + Test E/C; Equipoise seems to come to life with test, seems to be synergistic for some. At doses from 400-600mg/w see notable hardening, strength and size gain, increased appetite. I have insane hunger at 600 mg/wk. At 300 mg/w with 500+ mg/w the appetite is manageable and still I see some synergy. Add in an Aromatase inhibitor (AI) and one can get pretty hard and lean. I have had sore shoulders and pectoral tendinitis disappear on equipoise never to return relatively speaking.
Deca + Test E/C; Some synergy but for me at least not as noticeable. Lots of water weight so high weight gains. More difficult to manage estrogenic/"progestogenic" side effects with SERM or Aromatase inhibitor (AI). Some use Dosinex or Bromo. Still, for a strength and size only cycle this combination was very popular in the 80's and 90's and is very effective. Stacked with test in roughly a 1.5/1 (test/Deca) libido issues are often not a problem until in PCT, where it can emerge.
Over the decades there has been a trend going away from Deca and toward Equipoise. IMO Equipoise has less sides at reasonable doses (300 - 600 mg/w) than Deca at the same dosage. Personal experience shows me that Equipoise is better for tendinitis and joint pain than Deca. This may be related to Boldenone's capacity to convert to estrogens albeit at a lower rate than Testosterone, where Decadurabolin does not convert to estrogens at any appreciable rate. While both may increase collagen synthesis, estrogen is important in a more complex range of activities supportive of joint function. This could make a difference in some users especially when stacked with testosterone at moderate to high dose as it will negatively affect collagen synthesis. Personally, if I were to use a 19-nor compound it would be a trenbolone ester rather than a nandrolone ester... and at a lower dose no more than 400 mg/w and likely 1/2 to 3/4 that"